tag:blogger.com,1999:blog-1086997308146538942024-02-08T13:21:42.866+10:00julianh72's Blog of Interesting StuffThis Blog started out as a record of my project to build (and make things with) a Mendel Prusa 3D Printer (RepRap), but I have found that I keep getting sidelined into a lot of other interesting projects (Astronomy, Arduino, Raspberry Pi, etc), so I have widened its scope to cover anything and everything that I find interesting!Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.comBlogger92125tag:blogger.com,1999:blog-108699730814653894.post-21998137331015815702016-09-29T23:35:00.002+10:002016-09-29T23:35:47.467+10:00So I discovered a Wolf-Rayet star!<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">OK, I should admit right from the start that while I feel as though I have “discovered” a Wolf-Rayet star, it turns out to be very well-known to science, so I don’t think there is any chance that I will be invited to give it a name, less yet have it named after me!</span></div>
<b id="docs-internal-guid-85cbb383-7625-456b-e7c6-519bcaa88c7f" style="font-weight: normal;"><br /></b>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">(What’s a “Wolf-Rayet Star”? They are a class of extremely hot stars with unusual spectral signatures - while typical stars fuse hydrogen into helium, the Wolf-Rayets are busy fusing helium and heavier elements, so show bright emission lines for carbon, nitrogen and other heavier elements. Check out the Wikipedia article for a bit more information: </span><a href="https://en.wikipedia.org/wiki/Wolf%E2%80%93Rayet_star" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://en.wikipedia.org/wiki/Wolf%E2%80%93Rayet_star</span></a><span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> )</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">So here’s the story of how it unfolded: </span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">In my experimenting with backyard spectroscopy, I thought it would be interesting to capture a single spectral image with a group of several stars of comparable brightness but varying spectral classes, to illustrate the different spectral “signatures” side-by-side.</span></div>
<b style="font-weight: normal;"><br /></b>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">My first thought was to try a nice bright globular cluster, as there would be no shortage of stars - I aimed the telescope at 47 Tucanae (one of my favorite astronomical sights!), and grabbed a few spectra with varying exposures, but this turned out to be a bad choice for two reasons:</span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Firstly, there are simply too many stars (some millions of them), so all of the spectra just smear together into one fuzzy streak.</span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Secondly, like many globular clusters, it turns out that a very large fraction of its stars have very similar masses and compositions, so have very similar spectra, and the variation I was seeking to capture just isn’t there. (Sure, with a population of millions of stars, there are lots of “interesting” stars, but they are vastly outnumbered by the “boring” yellow G-class stars which make up the bulk of the population in 47 Tuc.)</span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">So what I needed was a small open cluster - small, because of the small capture area of my set-up (about 0.3 degrees wide x 0.24 degrees), and open, so that I might capture perhaps 10 comparably bright stars with their spectra, spread over the frame. A bit of a review of possible targets suggest NGC 6231 (a.k.a. Caldwell 76) as a good candidate - approximately 0.25 degrees across, and with a good spread of stars with Magnitude 6 to 7 approximately. </span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><br /></span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The following image is a DSS image of NGC 6231, showing an area of approximately ½ degree wide x ⅔ degree high (screen capture from SkySafari 5 Pro):</span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><img alt="NGC 6231.png" height="963" src="https://lh3.googleusercontent.com/Gvjf8ngnj03ncjD2x0qLyG5qA9lAF0_yaZXw4sNwZk0ITiAG0fOraspH5erEdeRcFWsT_Hh5dNgPoc-f7mmuhwED-aaW-EdTBFoX0J8eUMYCp8UpQnpc5GVusKfuFvzW-LRVzO5H" style="-webkit-transform: rotate(0.00rad); border: none; transform: rotate(0.00rad);" width="602" /></span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">So I aimed the telescope, focused the camera with Star Analyser SA100 grating, and captured the resulting spectra - and this is what I saw:</span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><img alt="BrightStars_205913 C76_g4_ap13_conv.png" height="481" src="https://lh3.googleusercontent.com/K55EQGypY52h6oJKX1WW03DtikTgarKZJc8Y0F2vPL_k3hbizPAWGUGyzj7yfv3ZDc5e3K9tj6Dtg7pURcD8-RiHrsbe0w0IrEu1xMMtjcd8PSaV76bVsu2ipytKMgXaWCZSrCFa" style="-webkit-transform: rotate(0.00rad); border: none; transform: rotate(0.00rad);" width="602" /></span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">At a quick glance, you can see about 12 stars on the left side of frame, with their spectra on the right of frame. (Even more stars and spectra can be extracted with a bit of post-processing and enhancement.)</span></div>
<b style="font-weight: normal;"><br /></b>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">As I was hoping, you can see a few different stellar “signatures” - some spectra are longer than others, some show some strong absorption lines, and so on - perfect, just what I was hoping for!</span></div>
<b style="font-weight: normal;"><br /></b>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">But look at the spectrum of the bright star at the mid-height of the frame - it looks very different to the others. You can see that it has several intense bright emission lines - what could this mean?</span></div>
<b style="font-weight: normal;"><br /></b>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The first thing I need to do is to extract the spectrum of the target star from the field, so that it can be analysed in isolation, without being “polluted” by the spectra of the neighbouring stars. There are a few ways to go about this, but one handy trick is to open the spectral image in your favourite photo editing software, draw a selection rectangle around the spectrum of interest, and copy and paste this into a new image. Then, resize the spectrum strip image to be just one pixel high (without changing the width) - this creates a 1-pixel high spectrum which averages the brightness of all the pixels that were in each column of pixels in the source image. Now, resize it again to about 30 pixels high, and you should end up with something like this:</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><br /></span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><img alt="HR 6265.png" height="20" src="https://lh6.googleusercontent.com/pRsk8YmwCoNvNfW7jR6VDfPjCiTSuCJsPavcFQcZ-bo-sKfy6giII_FTMDQlBKuin_f7ipqGzmyJhwXleLtsCL3nHiC3Oleu5RAQ9bQ9_xREc9dwrGlOxW24LUqz8omYpLMGYvk-" style="-webkit-transform: rotate(0.00rad); border: none; transform: rotate(0.00rad);" width="602" /></span></div>
<b style="font-weight: normal;"><br /></b>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">(Note that all image editing processes of this type can introduce “artefacts”, meaning you are losing some of your source data, and introducing some spurious “data”, but this approach should help you to get a useful spectral image which captures the main features well, at the possible expense of losing some of the fine detail, or introducing spurious fine data.)</span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Now, I loaded my spectrum into RSpec, calibrated the wavelength scale, and corrected for instrument response, and we see the following spectrum:</span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><img alt="HR 6265.png" height="305" src="https://lh5.googleusercontent.com/tBcXDFAfFtREj0eN7gwJCJb_hwJe4V2arA9ANXvps19oo4x09xFooLO8aTAGNkzVHxZ4Ed4HvYZoHQNw40_tbIQ_BINXeqPFU0v2LOdOmKaAy2IpwMuWkHUPCO46YOn15lMcHRqA" style="-webkit-transform: rotate(0.00rad); border: none; transform: rotate(0.00rad);" width="602" /></span></div>
<b style="font-weight: normal;"><br /></b>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Yes, those bright points that I saw in the original image have come through as strong emission lines, at wavelengths of about 4650, 5690, 5810, 6560 and 6730 Angstroms. </span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><br /></span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">And when we superimpose the characteristic lines of a Class WC star, we see excellent correlation with 4 of the classic WC emission lines - the bright emission lines that I spotted correspond to Carbon emission at 4650, 5696 and 5805 Angstroms, and Hydrogen-alpha emission at 6563 Angstroms:</span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><img alt="HR 6265 with WC Lines.png" height="305" src="https://lh4.googleusercontent.com/O1Oj0oYFTM7_8gROij9bl-mHnbXlOPc-dPLPQkGzzuJv-thbP9HwQvzGMMGcd_FmaWwZ12GFD6sqXMuvS3DgW-1j65hHLINKprje3IqhuR6soJDRS2mom9vfb2K-m9BLh8GVBjkI" style="-webkit-transform: rotate(0.00rad); border: none; transform: rotate(0.00rad);" width="602" /></span></div>
<b style="font-weight: normal;"><br /></b>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">So - mystery solved - Open Cluster NGC 6231 (C 76) contains a Wolf-Rayet star, with Spectral Class WC!</span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">This was an exciting “discovery” for me (even more so than my “discovery” of methane on Neptune! </span><a href="http://julianh72.blogspot.com.au/2016/09/methane-in-neptunes-atmosphere-from-my.html" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://julianh72.blogspot.com.au/2016/09/methane-in-neptunes-atmosphere-from-my.html</span></a><span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> ), so I started doing a bit of research - and discovered that NGC 6231 actually contains at least three Wolf-Rayet stars: HD 151932 (Mag. 6.48), HD 152270 (Mag. 6.61), and HD 152408 (Mag. 5.82). </span><a href="https://en.wikipedia.org/wiki/NGC_6231" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://en.wikipedia.org/wiki/NGC_6231</span></a><span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Sure enough, my “discovery” turns out to be the well-documented HD 152270 (a.k.a. HR 6265). Oh well - I guess my first real discovery will have to wait for another day!</span></div>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Nevertheless, I hope this little story expresses some of the genuine thrill that can be found in doing “real science” in your backyard!</span></div>
Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-5331472996447079082016-09-12T10:30:00.002+10:002016-09-12T10:32:51.187+10:00Detecting Methane in Neptune's Atmosphere - from my Backyard!<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">I am capturing stellar spectra using a 200 mm Meade LX-90 telescope with 0.63 Focal Reducer (Effective Focal Ratio f/6.3), QHY5 mono camera, and a Star Analyser SA100 grating. The camera is mounted on a “flip mirror” diagonal, which allows the telescope to be aligned visually with an eyepiece, and then the mirror is flipped out of the light path to the camera and grating.</span></div>
<b id="docs-internal-guid-c563714c-1bca-df4a-063a-e8b917d985f0" style="font-weight: normal;"><br /></b>
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<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><img alt="IMG_20160910_004331.jpg" height="339" src="https://lh6.googleusercontent.com/JMR0wg91pwBMf_KPDlAnpTXLBe4xzVmTJ2_9CqFPCb3Hn0HHLmfVjNRhwdsWxw7jA11NqtmvzQC88TRk7PYZ8HPoUEcideZ-pBIEFgnBdFPh4yPZt_3_i8nkHikeDNpQut9zSG4Z" style="-webkit-transform: rotate(0.00rad); border: none; transform: rotate(0.00rad);" width="602" /></span></div>
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<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The following image is a stacked composite of 8 x 60-second frames captured on the evening of 25 August 2016 from my light-polluted backyard in suburban Brisbane (Australia). Neptune had an apparent visual magnitude of 7.8 at the time. (The exposure is reasonable, but for an improved quality spectrum for analysis, a longer capture session with a greater number of stacked frames would have helped.)</span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Neptune is at centre-left, with its spectrum spread across the centre of frame, and there are three other unidentified “field stars” visible in the frame. (Could the dim star just below and left of Neptune be Triton?) </span></div>
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<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><br /></span></div>
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<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><img alt="Sat_221751 Neptune_g4_ap5 Cropped.jpg" height="555" src="https://lh3.googleusercontent.com/ERTHzB_P5hLg1bABxmjwA4IN7fqOA7UGY1L3bKOSV358swY6BKm3yQwwSX0Y1hR4AFHVIdZiYXzzvceU3R0hGp08I7NQ8rZ4evwFh_XBuPhEKea-9UXGPcI2kNu2WGcdNsXd4hPw" style="-webkit-transform: rotate(0.00rad); border: none; transform: rotate(0.00rad);" width="602" /></span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><span style="font-size: 14.6667px; line-height: 20.24px;">There are some conspicuous dark absorption bands in the spectrum of Neptune - let’s see if we can work out what we’re looking at.</span></span></div>
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<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><br /></span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The spectrum image was loaded into the RSpec spectral analysis program, which reads the intensity of the image and produces a graph of intensity vs wavelength. (Note that even though the spectrum is captured in B&W, the software can synthesise the visible colours.)</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><br /></span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><img alt="Neptune - Stacked Frames - Uncorrected - With BW Spectrum.jpg" height="304" src="https://lh4.googleusercontent.com/c5sJ23sC-ihi_XT8Bio04YCx3fxOSUo4AKQlEplWUYk3cY5AEHwbxfSYDRDZFYdaxF-QE2OXckYnRBMJ5rTmBxy1XUFwnMtIjr6Llae-OrlpPN8qJMZkaz3nZwCA8LvThcikw2mb" style="-webkit-transform: rotate(0.00rad); border: none; transform: rotate(0.00rad);" width="602" /></span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><img alt="Neptune - Stacked Frames - Uncorrected.jpg" height="304" src="https://lh5.googleusercontent.com/s6kTGvsLsihBw4Fw4ouNVP2tpbSACdDTWvq_rU_kGOFB3b5TK6jkqDVe1Dv_fODttTuVQCG5mLxz8-NZctAVIc8GOraJybsFzG-CRb5Kg4n5cameVae1YadKqKqycNt1vZXtfxPQ" style="-webkit-transform: rotate(0.00rad); border: none; transform: rotate(0.00rad);" width="602" /></span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Note the “bell curve” shape of the spectrum plot - this is largely due to the varying sensitivity of the camera for different wavelengths. The camera is designed to capture visible light, with peak sensitivity in the green, diminishing sensitivity in the blue and red, very limited sensitivity in the Ultraviolet (< 4000 Å), and limited sensitivity in the Infrared (> 7500 Å).</span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">When we calibrate for the Instrument Response, we get the following graph, which better represents the ACTUAL relative intensity of the spectrum across the range of visible wavelengths.</span></div>
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<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><br /></span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><img alt="Neptune - Corrected.jpg" height="304" src="https://lh6.googleusercontent.com/ZSmNoXGtslY2X9RQysHvJOuf_sfz1DMvP43Gjf7YcPCwpmlvUND-nna_lem8bN5nzd4A8rVUiE-tFCF1JfGVl8ReDbVkVmPhj3OMBBdohA0XuWPtDtbn0BiNflif1rUsUns5w6FP" style="-webkit-transform: rotate(0.00rad); border: none; transform: rotate(0.00rad);" width="602" /></span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Neptune shines in reflected sunlight - and the Sun is a Class G2V star. When we overlay a classic G2V spectrum, we can see that the spectrum of Neptune broadly follows the same shape, but there are some conspicuous absorption bands which are not seen in the Sun’s spectrum - what could these be?</span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><img alt="Neptune - Corrected - with G2v.jpg" height="304" src="https://lh4.googleusercontent.com/d_-U-sIfhmGzHKIxAQWdpS8IX_QfziTIZ6QVlK-5g6DsZhMClPHXz01yniSVIpzrmsBKYmdf2TvOwJqA-6IwvXEo4tqqTTjsereYgr8Tg2jlYMWJE9vi2IduRPlBs9lLyenJ9HZf" style="-webkit-transform: rotate(0.00rad); border: none; transform: rotate(0.00rad);" width="602" /></span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Methane is commonly known for its absorption in the infrared (hence its significance as a Greenhouse Gas in the Earth’s atmosphere), but it also has a number of absorption / emission lines in the visible spectrum, at wavelengths of 4860, 5430, 5760, 5960, 6190 & 6680 Å. </span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">When we overlay these lines on the spectrum, we see an excellent correlation. Bingo! Neptune’s atmosphere is confirmed to contain a significant amount of Methane! </span></div>
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<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><br /></span></div>
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<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> </span><span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><img alt="Neptune - Corrected - with Methane Lines.jpg" height="304" src="https://lh4.googleusercontent.com/A_72D4Teuaqb7E_cRwc1NpV6THqAKBrEnIichrZyNa8XT_ZMPY8AfG-GpF39We705qEciytRsOI8WWhyC3WkSQlAXnS6tm-mUu6zHmN1XdqrwTJTJWg1s_-OUcp52Ua8DLSgDGTD" style="-webkit-transform: rotate(0.00rad); border: none; transform: rotate(0.00rad);" width="602" /></span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: "arial"; font-size: 14.666666666666666px; font-style: normal; font-variant: normal; font-weight: 400; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">This may not come as any news to experienced planetary scientists (I don't think NASA needs to launch a mission to confirm my “findings”!), but I find it quite astonishing what can be accomplished by a very inexpert amateur with very modest equipment in their backyard! </span></div>
Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-41396704691674455622016-05-26T09:50:00.000+10:002016-05-26T09:50:38.963+10:00Yes, people really do 3D CAD on Mobile devices!I've been using OnShape <a href="https://www.onshape.com/">https://www.onshape.com/</a> as my primary 3D modelling package for some time now - both for designing parts for my hobby 3D printing and laser cutting, and also for general work (engineering) applications.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp80okgnLilcKMHBlX-_prUKrSZAr0pM5eEZqoZAjB1I-soUBKOmE0TWDLxNKeBoCNKJqH_xVuZOKiytepluCKctZSALWakhRviQx1rnsHXEyD0cXRFE-_TntCW8yKjLIY0JakNOHtWJo/s1600/OnShape+capture.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="184" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp80okgnLilcKMHBlX-_prUKrSZAr0pM5eEZqoZAjB1I-soUBKOmE0TWDLxNKeBoCNKJqH_xVuZOKiytepluCKctZSALWakhRviQx1rnsHXEyD0cXRFE-_TntCW8yKjLIY0JakNOHtWJo/s320/OnShape+capture.JPG" width="320" /></a></div>
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You can check out my early quick review here: <a href="http://julianh72.blogspot.com.au/2015/08/affordable-free-3d-modelling-software-5.html">http://julianh72.blogspot.com.au/2015/08/affordable-free-3d-modelling-software-5.html</a> - and the more I've used it, the more impressed I've been.<br />
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I use OnShape primarily via Chrome browser on a Windows laptop (work or home) or a Windows tablet or a Chromebook, but I also use it on my Android tablet (and it is also available for iPads). What surprises many people is that OnShape can truly be used for full-featured 3D modelling (not just viewing) on mobile devices.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhRBgQkhq6pFBbv93F0y8dZ8ieOYniynSBnVkBN46cYhchWalCqdbuDM-M0ELGEDarBcGEQ3CwXrTbt2ZT5M-co0bhiUg28q3-QAu0Y5zli72d6tc5nDb2PSZ-24VcSirnIsAPA7sjSdGA/s1600/Onshape+app+on+Android+tablet.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhRBgQkhq6pFBbv93F0y8dZ8ieOYniynSBnVkBN46cYhchWalCqdbuDM-M0ELGEDarBcGEQ3CwXrTbt2ZT5M-co0bhiUg28q3-QAu0Y5zli72d6tc5nDb2PSZ-24VcSirnIsAPA7sjSdGA/s320/Onshape+app+on+Android+tablet.png" width="320" /></a></div>
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OnShape have just released a blog post "YES, PEOPLE REALLY DO CAD ON MOBILE!" <a href="https://www.onshape.com/cad-blog/yes-people-users-really-do-cad-on-mobile?utm_source=hs_email&utm_medium=email&utm_content=29936753&_hsenc=p2ANqtz-_jJNrK2qf9-xSiJlTvoqBOoscIhi_lDT2Vjq5p3JUpel2rp7KPKmYUU2SwkCkRlqVDaBJJ5WUiwAwE5vgIpQKm9UIODA&_hsmi=29936753">https://www.onshape.com/cad-blog/yes-people-users-really-do-cad-on-mobile?utm_source=hs_email&utm_medium=email&utm_content=29936753&_hsenc=p2ANqtz-_jJNrK2qf9-xSiJlTvoqBOoscIhi_lDT2Vjq5p3JUpel2rp7KPKmYUU2SwkCkRlqVDaBJJ5WUiwAwE5vgIpQKm9UIODA&_hsmi=29936753</a> which gives some actual statistics which demonstrate that people really are using OnShape Mobile for modelling and design, not just viewing. While browser use is an order of magnitude bigger than mobile use (as you would expect), it is interesting to note that the usage patterns mimic each other on both platforms, except on weekends and holiday periods, where mobile use sees proportionately less of a dip than browser use - indicating it is the "platform of choice" for many users when you are away from the office.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEieRPhnu9ZkjjzJx38lsb7tOUmPmspHStMtX1SN5C9vCRn3K_KAQHpnLcuyaMhOLLHYP9L6J2lQ4GhjnhHBR19U-ENrEDP5KyPMQIzeD-zP5drCTGp9ATUVE0_E3sx32gt3-1PurTvObPA/s1600/OnShape+Browser+vs+Mobile.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="214" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEieRPhnu9ZkjjzJx38lsb7tOUmPmspHStMtX1SN5C9vCRn3K_KAQHpnLcuyaMhOLLHYP9L6J2lQ4GhjnhHBR19U-ENrEDP5KyPMQIzeD-zP5drCTGp9ATUVE0_E3sx32gt3-1PurTvObPA/s320/OnShape+Browser+vs+Mobile.png" width="320" /></a></div>
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If you are looking for a capable low-cost (free!) 3D modelling package for your hobby use, you really need to check out OnShape, if you have not done so already!Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-75801408496668556162016-04-14T16:28:00.001+10:002016-04-14T16:29:30.947+10:00Some reasonable planetary images with my ZWO ASI120MC cameraWhile seeing wasn't great from my home in inner-western Brisbane last night (13 April), it was nice and dark and clear, so I set up my Meade 200 mm LX90 (GoTo Alt-Az mount) with ZWO ASI120MC (one-shot colour camera) <a href="http://julianh72.blogspot.com.au/2014/09/zwo-asi120mc-planetary-camera-quick.html">http://julianh72.blogspot.com.au/2014/09/zwo-asi120mc-planetary-camera-quick.html</a>, and fired off a few 30-second video captures with FireCapture, and then stacked and sharpened in AutoStakkert to get the best images that I could.<br />
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Jupiter was nice and high in the sky:<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKBdpl_6MkS7vL3gE2Zv5eExoQZeFP2gNXtq62MMEF64KAaPKLi1yH2BrxNVqFVtrf5agsKkLgyW0MhDIo0p2d8IjfXltpnGKDMpI7POa-HQnrx-uACjl8y7GwXQtTmz2UgcuSuj98RbQ/s1600/Jupiter+1+-+13-Apr-2016.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="274" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKBdpl_6MkS7vL3gE2Zv5eExoQZeFP2gNXtq62MMEF64KAaPKLi1yH2BrxNVqFVtrf5agsKkLgyW0MhDIo0p2d8IjfXltpnGKDMpI7POa-HQnrx-uACjl8y7GwXQtTmz2UgcuSuj98RbQ/s320/Jupiter+1+-+13-Apr-2016.jpg" width="320" /></a></div>
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And the Great Red Spot came into view nicely later in the evening:<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEit7m5Hhw0GhF13ZI9GX2GoZpire7zMgldfRiXE7LtXyi9TGZoYzgaJR4AxancAULFy_Cv09I85LOZUiU25xyJukeCnDCudUXQQMHflbtMfUzwc6OSp0PgZrQ-8GOa0b1s95jziJlhFdOE/s1600/Jupiter+2+-+13-Apr-2016.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="280" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEit7m5Hhw0GhF13ZI9GX2GoZpire7zMgldfRiXE7LtXyi9TGZoYzgaJR4AxancAULFy_Cv09I85LOZUiU25xyJukeCnDCudUXQQMHflbtMfUzwc6OSp0PgZrQ-8GOa0b1s95jziJlhFdOE/s320/Jupiter+2+-+13-Apr-2016.jpg" width="320" /></a></div>
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Mars and Saturn were fairly low in the sky, sitting in the sky-glow of Brisbane City to the east (and directly over my roof), so while I'm fairly happy with these shots, I hope to get some better images in a couple of months when they're a bit higher as well.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-3P3Q6Q7Z6kq98_r2YJeIfYY5y8oVn7ZD1FQ5PHxCCboR-TQey8HA_xKTQnfgaCrMk3cmcFs96cGZyDKbIrYCvKgtAw7dTyqzPrKAGlb4YwzWut_aQPvpClVZkVMtFAblsfI2ttyQLGg/s1600/Saturn+-+13-Apr-2016.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="251" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-3P3Q6Q7Z6kq98_r2YJeIfYY5y8oVn7ZD1FQ5PHxCCboR-TQey8HA_xKTQnfgaCrMk3cmcFs96cGZyDKbIrYCvKgtAw7dTyqzPrKAGlb4YwzWut_aQPvpClVZkVMtFAblsfI2ttyQLGg/s320/Saturn+-+13-Apr-2016.jpg" width="320" /></a></div>
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My best videos were taken without a Barlow - I just couldn't seem to get quite as sharp focus with my 2x Barlow. Maybe I need to try focussing with a Bahtinov mask on a nearby star before pointing at my target?<br />
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These are the best of last night's efforts - they may not rival Hubble, but I'm pretty happy with them.Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-53378288634304994172016-03-31T14:25:00.000+10:002016-03-31T14:25:00.323+10:00Use your phone / tablet as a 3D printer?!This 3D Printer concept uses your smartphone or tablet as the light source to cure photo-resins.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg83vXOHLPxHVpvD0ngodlZl6btY4Plmjo0pt-pIp3DDb87OD7dzaa9YJLs6rGuElt-8UYOM3GZi8oFZ3IMShUVsNzoPkrcLmvvs8sTZH1mMrTG52YLNsUPL9ud9w96ZNkj_kXAmytD5QE/s1600/08.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="179" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg83vXOHLPxHVpvD0ngodlZl6btY4Plmjo0pt-pIp3DDb87OD7dzaa9YJLs6rGuElt-8UYOM3GZi8oFZ3IMShUVsNzoPkrcLmvvs8sTZH1mMrTG52YLNsUPL9ud9w96ZNkj_kXAmytD5QE/s320/08.jpg" width="320" /></a></div>
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<span id="goog_772969586"></span><span id="goog_772969587"></span><br />
Virtually silent, runs off 4 x AA batteries.<br />
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And the best bit?<br />
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It's only $99 for the printer (build volume: 76 mm x 128 mm x 52 mm; vertical build rate of about 10 mm/hour or so), and $15 for a 100 mL bottle of resin (a range of hard and flexible resins available); prints with virtually no waste.<br />
<br />
http://www.olo3d.net/<br />
https://www.kickstarter.com/projects/olo3d/olo-the-first-ever-smartphone-3d-printer<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiA_KpzoaV_Nx9t0KNpe6qnSHrcVoZpUwLmoGJ20iYC66Ei9xxsbyIkVHvo6g_KmFhxMb6TMan0SaD4Ur_eX4QoX8Lf0lvUcp9N1pld5t4HjW8j5UoyPSROR7aqIpP9mmiBTyHZLcPk_Do/s1600/01.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="180" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiA_KpzoaV_Nx9t0KNpe6qnSHrcVoZpUwLmoGJ20iYC66Ei9xxsbyIkVHvo6g_KmFhxMb6TMan0SaD4Ur_eX4QoX8Lf0lvUcp9N1pld5t4HjW8j5UoyPSROR7aqIpP9mmiBTyHZLcPk_Do/s320/01.jpg" width="320" /></a><br />
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I want one! <br />
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It sounds too good to be true - I'll believe this is a real thing when I see one actually working.<br />
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(But to quote “The X-Files”: <i>I want to believe!</i>)Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-71670420825473299212015-12-17T09:57:00.001+10:002015-12-17T10:00:40.044+10:00Netflix Socks - automatically pause your binge-watching if you fall asleep!So the Paris Climate Conference went well, and we have apparently solved the problem of global warming - what's the next major problem humanity should tackle?<br />
<br />
Well, it's obvious really:<br />
<br />
You're binge-watching your favourite TV series on Netflix, you fall asleep, and you wake up two hours later having missed a couple of key episodes.<br />
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The good people at Netflix have a simple solution that you can make for yourself:<br />
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Netflix Socks <a href="http://makeit.netflix.com/netflix-socks">http://makeit.netflix.com/netflix-socks</a><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjaaJLYnxPP_P6objQey9OYR1yO6TtXwo4A0pEW53pAe1ULV06mmFd7K0u5Z6YBHHPtI3PGBx_Xz22T8xYaNnqw4SSabdnkVZQIEbiubvy2dejgueU8-mZsmFd8HJQhDERnE8uwvB4Zo_Y/s1600/Netflix+Socks.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="192" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjaaJLYnxPP_P6objQey9OYR1yO6TtXwo4A0pEW53pAe1ULV06mmFd7K0u5Z6YBHHPtI3PGBx_Xz22T8xYaNnqw4SSabdnkVZQIEbiubvy2dejgueU8-mZsmFd8HJQhDERnE8uwvB4Zo_Y/s320/Netflix+Socks.JPG" width="320" /></a></div>
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These amazing socks detect when you have dozed off, and send a pause signal to your TV / set-top box. A bright LED flashes a warning, so that you can press the over-ride button if you are awake and just happen to be sitting very still.<br />
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You can install the Netflix Socks adapter into your favourite pair of comfortable TV-watching socks, or you can download the knitting patterns to theme with your favourite Netflix shows, including Bloodline, Unbreakable Kimmy Schmidt, BoJack Horseman or House of Cards.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgUQ_2WgtVhg9tFWYHHLTpPKTYV2tGM1UynlCRd1CgkDCp9v6G0TydE99Uu5u63-Z_9Uj4L63XiSNIaaJyWUGp7zqKnVt2VeipbMoyrYEuoLA8AWa0oDqydkt7IPj5akwMa5rJo5hM3_7w/s1600/Bloodline+Socks.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgUQ_2WgtVhg9tFWYHHLTpPKTYV2tGM1UynlCRd1CgkDCp9v6G0TydE99Uu5u63-Z_9Uj4L63XiSNIaaJyWUGp7zqKnVt2VeipbMoyrYEuoLA8AWa0oDqydkt7IPj5akwMa5rJo5hM3_7w/s320/Bloodline+Socks.JPG" width="303" /></a></div>
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<a href="http://makeit.netflix.com/patterns/templates.zip">http://makeit.netflix.com/patterns/templates.zip</a><br />
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The parts list <a href="http://makeit.netflix.com/netflix_socks_materials_list.pdf">http://makeit.netflix.com/netflix_socks_materials_list.pdf</a> is pretty simple:<br />
<ul>
<li></li>
<li>A pair of TV-watching socks (raid your sock drawer, or knit a pair of Bloodline socks)</li>
<li>Arduino microcontroller (get one of the tiny "wearable" models, such as the Arduino Pro Trinket <a href="https://learn.adafruit.com/introducing-pro-trinket/setting-up-arduino-ide">https://learn.adafruit.com/introducing-pro-trinket/setting-up-arduino-ide</a> or AdaFruit Gemma <a href="https://www.adafruit.com/products/1222">https://www.adafruit.com/products/1222</a>)</li>
<li>IR LEDs (to control the TV)</li>
<li>LED indicator light (to alert you that the Pause function is about to trigger)</li>
<li>Battery</li>
<li>Momentary button (the over-ride switch)</li>
<li>Accelerometer</li>
<li>12” x 12” piece of felt</li>
</ul>
You should be able to make yourself the adapter for a few dollars, or you may even already have most of the parts if you have tinkered with Arduino before.<br />
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Enjoy!<br />
<br />Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-39977144586824595352015-11-27T08:27:00.000+10:002015-11-27T08:39:12.705+10:00Survey results: "Color Vision and the Efficacy of EnChroma Glasses"Blake Porter has published the results of his on-line survey <a href="http://www.blakeporterneuro.com/color-vision-efficacy-enchroma-glasses/">http://www.blakeporterneuro.com/color-vision-efficacy-enchroma-glasses/</a> into the efficacy of EnChroma sunglasses as an aid for compensating for colour blindness. He previously published a fantastic piece entitled <i>"What is color? Enchroma glasses, neuroscience, and the mystery of color"</i> <a href="http://www.blakeporterneuro.com/enchroma-neuroscience-color/">http://www.blakeporterneuro.com/enchroma-neuroscience-color/</a>, which I mentioned in an earlier post <a href="http://julianh72.blogspot.com.au/2015/09/fantastic-article-on-enchroma-glasses.html">http://julianh72.blogspot.com.au/2015/09/fantastic-article-on-enchroma-glasses.html</a> - do take a look at this article, if you have not already done so - it is a fascinating read and very thought-provoking.<br />
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A total of 406 people responded to the survey, so it is a useful sample size. A significant majority of respondents were males in their twenties, which is not really surprising - males are more commonly affected by colour blindness than females, and the poll was conducted as an on-line survey, so some internet-savvy was required to even be aware of the poll, and then to complete it.<br />
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And the results of the survey?<br />
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In a nutshell - they really do work, for the majority of users.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEwNWVtIT1kZqCTueMwQPhyxIPDlukkKV_V_LYl_9dnEi2YFG7pEpVg_RNgkfO4PSbwnZLuZi5UZwxFc5XIxwaGQDu8oV7Vc2mkmyzdASSXhs6B8QIgJp9S_zVMktftDJKz7stYAYocdM/s1600/EnChroma-effective-time.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="188" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEwNWVtIT1kZqCTueMwQPhyxIPDlukkKV_V_LYl_9dnEi2YFG7pEpVg_RNgkfO4PSbwnZLuZi5UZwxFc5XIxwaGQDu8oV7Vc2mkmyzdASSXhs6B8QIgJp9S_zVMktftDJKz7stYAYocdM/s320/EnChroma-effective-time.png" width="320" /></a></div>
<a href="http://i1.wp.com/www.blakeporterneuro.com/wp-content/uploads/2015/11/EnChroma-effective-time.png">http://i1.wp.com/www.blakeporterneuro.com/wp-content/uploads/2015/11/EnChroma-effective-time.png</a><br />
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You really need to read the whole article to get the full picture, but the Conclusion sums it up pretty well:<br />
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<h3 style="background-color: white; box-sizing: border-box; color: #333333; font-family: Lato; font-size: 28px; font-weight: 400; line-height: 40px; margin-bottom: 10px; margin-top: 10px;">
Conclusion</h3>
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What we may conclude with some certainty is that people who have a language full of color words, are color blind, and then use corrective means to aid their color blindness, new conscious color perceptions are near instantaneous, possibly due to the broad processing capacity of the visual system, and there seems to be an intuition present, possibly due to knowledge from language, allowing these people to correctly assign their new colors with language. Overtime, their processing of new colors and their ability to discriminate across colors will be improved and the time course of this may be age dependent.</div>
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<span style="background-color: white; color: #444444; font-family: "verdana" , "geneva" , sans-serif; font-size: 14px; line-height: 20px;">The work by Blake Porter is licensed under a </span><a href="http://creativecommons.org/licenses/by-nc-sa/4.0/" rel="license" style="background-color: white; box-sizing: border-box; color: #0b6bbf; font-family: Verdana, Geneva, sans-serif; font-size: 14px; line-height: 20px; text-decoration: none;">Creative Commons Attribution-Non Commercial-ShareAlike 4.0 International License</a>Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-11144336192607146472015-11-26T12:29:00.000+10:002015-11-26T12:29:34.305+10:00Ultrascope - Open-Source Automated Robotic ObservatoryHere's one for the Geeks and Makers:<br />
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Ultrascope - an open-source Automated Robotic Observatory:<br />
<a href="http://www.openspaceagency.com/ultrascope/">http://www.openspaceagency.com/ultrascope/</a><br />
<a href="https://www.onshape.com/cad-blog/who-wants-to-go-hunting-for-asteroids">https://www.onshape.com/cad-blog/who-wants-to-go-hunting-for-asteroids</a><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj0cam2dRZXr6w7ZQAorlEu9oohWESbvXttt-55qx0v4tvAfxY7N3L4pBPHhftKQoYCH0Lm8go_fBbIY8-TEXR1N2v6MM9MVACcpWGp695i3KtKj9SEPl2Hhb2JkMTVFRbjM07o13h4KRM/s1600/Ultrascope+in+Onshape+3D+CAD.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="180" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj0cam2dRZXr6w7ZQAorlEu9oohWESbvXttt-55qx0v4tvAfxY7N3L4pBPHhftKQoYCH0Lm8go_fBbIY8-TEXR1N2v6MM9MVACcpWGp695i3KtKj9SEPl2Hhb2JkMTVFRbjM07o13h4KRM/s320/Ultrascope+in+Onshape+3D+CAD.png" width="320" /></a></div>
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The Ultrascope project (currently in pre-Beta) aims to develop a kit-set robot telescope (or ARO - Automated Robotic Observatory), that will allow amateur astronomers to contribute to citizen science projects for a radically reduced cost - e.g. asteroid hunting, etc.<br />
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The first project is the Explorer Series Ultrascope, which is a 90 mm (3.5 inch) reflector ARO that is able to conduct celestial photography and photometry. The kit will be released as open-source plans for 3D printing or laser cutting, paired with an Arduino controller and a high-pixel smartphone (eg Lumia 1020 with 41 Megapixel CCD).<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjVV6EVHZiIeJED3j904Ik93K3YTIAXFWCuo2_ftitNpwBxTeCGHXqFb0Ja6XBkEvycxHLHEVnE0gSKrrYmhcoQ8J4WAXDb9dXlhHJ88pGPiWCHxP9ovmQFmwkueXmGhmFZhbOekqZqmQk/s1600/Ultrascope+Blueprint.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="226" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjVV6EVHZiIeJED3j904Ik93K3YTIAXFWCuo2_ftitNpwBxTeCGHXqFb0Ja6XBkEvycxHLHEVnE0gSKrrYmhcoQ8J4WAXDb9dXlhHJ88pGPiWCHxP9ovmQFmwkueXmGhmFZhbOekqZqmQk/s320/Ultrascope+Blueprint.png" width="320" /></a></div>
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They are also working on a 200 mm (8") version, the Odyssey.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiuNlYT7ntzEymxfz48pczMneD9rfFz3n47R_Ao9Lm1hgVvTDo63uEQn23FHxWXT0yS2b_7oFSx2gHYcAbGj77GitFR0EdvptcaABCrv6dD8CuvaFi9jA9um1qnwsqc4lN7vJ_WstZgsYw/s1600/Ultrascope+Odyssey.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="146" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiuNlYT7ntzEymxfz48pczMneD9rfFz3n47R_Ao9Lm1hgVvTDo63uEQn23FHxWXT0yS2b_7oFSx2gHYcAbGj77GitFR0EdvptcaABCrv6dD8CuvaFi9jA9um1qnwsqc4lN7vJ_WstZgsYw/s320/Ultrascope+Odyssey.png" width="320" /></a></div>
<br />Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-44849111335675736792015-10-27T12:37:00.001+10:002015-10-27T12:42:36.650+10:00Things I wish somebody had told me when I started building a RepRap 3D PrinterOr to be more accurate:<br />
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<i><b>Things people told me which I wish I had listened to more attentively when I started building a RepRap 3D Printer</b></i><br />
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My RepRap is a 1st-generation Prusa Mendel <a href="http://reprap.org/wiki/Prusa_Mendel_(iteration_1)">http://reprap.org/wiki/Prusa_Mendel_(iteration_1)</a> which was pretty much the bee's knees in affordable DIY 3D printing back in August 2011 <a href="http://julianh72.blogspot.com.au/2011/08/first-post-inspirations.html">http://julianh72.blogspot.com.au/2011/08/first-post-inspirations.html</a>.<br />
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I bought a kit of plastic bits and "vitamins " (nuts and bolts etc) on eBay, and self-sourced all of the other components (stepper motors, electronics, etc). The buy-and-build process was itself instructional (and fun!), and about two months after construction commenced, I had a workable 3D printer in operation. <a href="http://julianh72.blogspot.com.au/2011/10/cheers.html">http://julianh72.blogspot.com.au/2011/10/cheers.html</a><br />
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The Prusa Mendel and its predecessors truly embodied one of the core philosophies of the RepRap Project: RepRap is short for <b>Rep</b>licating <b>Rap</b>id-Prototyper; that is, the 3D printer can (almost) build itself. To this end, the maximum possible number of components were made from 3D-printed plastics, right down to the z-axis couplers and axis bushes.<br />
<br />
These days, if you start a similar adventure, you are more likely to try building a 3rd-generation Prusa i3 <a href="http://reprap.org/wiki/Prusa">http://reprap.org/wiki/Prusa</a> or similar. To the uninitiated, it is hard to see how the Prusa i3 is directly related by just two generations from the Prusa Mendel, but for those of us "in the know", the family heritage is obvious.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg4NDgwOtkGT_qq1QusLlc6l2bHdbTjtF70AK8TI8-9QC-3LAW8-HIm0v_uOHvqJoOBa7WKT-b0eZpfQwEb3dZigvQ6FThIemczzQvEyTDFr8EoDN6siVHq2120xCltt2QmGc_n9055Qs0/s1600/Prusa+Mendel+i1.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg4NDgwOtkGT_qq1QusLlc6l2bHdbTjtF70AK8TI8-9QC-3LAW8-HIm0v_uOHvqJoOBa7WKT-b0eZpfQwEb3dZigvQ6FThIemczzQvEyTDFr8EoDN6siVHq2120xCltt2QmGc_n9055Qs0/s320/Prusa+Mendel+i1.jpg" width="300" /></a></div>
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1st-Generation Prusa Mendel (Ref: <a href="http://reprap.org/wiki/File:Assembled-prusa-mendel.jpg">http://reprap.org/wiki/File:Assembled-prusa-mendel.jpg</a> )</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh10000qNOPRH0d0uE60FVRjxsD3DbE5Ww1-n4N4X0pmcDk6PJwmC1aQiCLnNcq3JIGf_eMiEi3jD3dFDl_aBW35_iYD7HxEDDi26BjiIT3AlAjV1KwD0MJhtf0-pBAimIw66BQap4gmd0/s1600/Prusa+i3.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh10000qNOPRH0d0uE60FVRjxsD3DbE5Ww1-n4N4X0pmcDk6PJwmC1aQiCLnNcq3JIGf_eMiEi3jD3dFDl_aBW35_iYD7HxEDDi26BjiIT3AlAjV1KwD0MJhtf0-pBAimIw66BQap4gmd0/s320/Prusa+i3.jpg" width="283" /></a></div>
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Current-generation (October 2015) Prusa i3 (Ref: <a href="http://reprap.org/wiki/File:Prusai3-metalframe.jpg">http://reprap.org/wiki/File:Prusai3-metalframe.jpg</a> )</div>
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The Prusa i3 (and other current-generation 3D printers) embody the accumulated learnings of both the originators of the RepRap Project, and thousands of RepRappers. The kits are cheaper than ever, but use a variety of materials and forms of construction, with less of an emphasis on using 3D printed materials for all components, for reduced cost and increased reliability / performance. (Steel or aluminium are just better at some jobs than plastic!)</div>
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Some may argue that this somehow "dilutes" the essence of RepRap, but for me, it makes the goal of ownership of an affordable and reliable 3D printer far more attainable, while still allowing freedom for experimentation and development/. (One of the great advantages of going down the open-source path, rather than buying a proprietary model, is that you can modify and upgrade your machine as often as you like, sharing your experience with that of many other like-minded individuals, so your humble beginnings can evolve into something better and better.)</div>
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In no particular order, here are my main learnings over the past few years:</div>
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<ol>
<li>You <b>NEED </b>proper mechanical linear bearings on all axes - 3D-printed PLA bushings are a nice philosophical concept, but realistically, the motion will be MUCH smoother and jitter-free if you install linear bearings (LM8UU or similar). Do yourself a favour, and buy a kit which uses them (most modern kits do), of else, print yourself some replacement carriage parts which are designed for LM8UU bearings instead of PLA bushings, and install them as soon as possible. <a href="http://julianh72.blogspot.com.au/2011/11/smooth-operator.html">http://julianh72.blogspot.com.au/2011/11/smooth-operator.html</a></li>
<li>You <b>NEED </b>a heated print-bed. Yes, it is possible to print on painter's tape etc, but life is MUCH easier when you have a heated print-bed. <a href="http://julianh72.blogspot.com.au/2011/12/hotbed-of-intrigue.html">http://julianh72.blogspot.com.au/2011/12/hotbed-of-intrigue.html</a> And this leads us to ...</li>
<li>You need a power supply with heaps of capacity. I started off with a hacked ATX power-supply <a href="http://julianh72.blogspot.com.au/2011/08/my-parts-list-power-supply.html">http://julianh72.blogspot.com.au/2011/08/my-parts-list-power-supply.html</a> which I thought had enough capacity (16 amps @ 12 volts), and while it did work, it turned out that it had trouble maintaining full supply voltage under heavy load. I have replaced it with a more robust true 15-amp sustained (18-amp peak) power supply <a href="http://julianh72.blogspot.com.au/2015/10/powertech-mp-3800-0-24-volt-power.html">http://julianh72.blogspot.com.au/2015/10/powertech-mp-3800-0-24-volt-power.html</a> , and it runs much better now.</li>
<li>Get rid of the 3D-printed Z-axis couplers, and replace them with engineered metal shaft couplers. You can pick up 5 mm x 8 mm aluminium couplers for a couple of dollars on eBay, and I have found that they grip the smooth stepper motor shafts much better than a plastic clamp - of which, I printed and installed quite a few design variants <a href="http://julianh72.blogspot.com.au/2011/11/smooth-operator.html">http://julianh72.blogspot.com.au/2011/11/smooth-operator.html</a>. (This is particularly important for a machine like the 1st-gen Prusa Mendel where the X-Axis is suspended from the Z-Axis motors; possibly less of an issue on the Prusa i3, where the motors are at the bottom, so the couplers are in compression, not tension.) They also run MUCH smoother, as they are able to take up the angular and offset errors between the motor and the threaded rod with a more reliable spring stiffness than the plastic clamp couplers.</li>
<li>Get yourself an LCD Controller, like the RepRapDiscount Smart Controller <a href="http://reprap.org/wiki/RepRapDiscount_Smart_Controller">http://reprap.org/wiki/RepRapDiscount_Smart_Controller</a> - this will allow you to print without a computer attached, freeing up desk-space, and also removing one link from the failure chain. These can be bought very cheaply on eBay - highly recommended.</li>
<li>If you are running an old-generation plastic-bodied print-head (PTFE and / or PEEK), replace it with an all-metal print-head with a heat-sink and fan. These run MUCH more reliably than the old PTFE-bodied print heads, and are also much more physically robust, and are able to withstand the occasional (and inevitable) print-head crash.</li>
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My 1st-generation Prusa Mendel has had all of the above upgrades applied to it - it is still physically the same arrangement as it stared life, but it now prints much more reliably and smoothly (and faster) than it did before. Dare I think that the "tinker and upgrade" phase has ended, and my RepRap will now enter a long mature life of production printing without significant additional upgrades?</div>
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(Naaah! Who am I kidding?! Of course I'll keep upgrading it - just watch this space!)</div>
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(As in all matters of opinion, some of these points may be controversial - for example, I am sure that some people have printed very successfully with 3D-printed PLA bushings, and continue to do so, but in my opinion, you are more likely to print successfully, and much more quickly, if you use linear bearings on all axes.)</div>
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<br />Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-80311871145804394372015-10-23T08:31:00.002+10:002015-10-23T08:33:20.332+10:00PowerTech MP-3800 0-24 volt power supply - a quick reviewI have been powering my RepRap 3D printer with a hacked ATX power supply <a href="http://julianh72.blogspot.com.au/2011/08/my-parts-list-power-supply.html">http://julianh72.blogspot.com.au/2011/08/my-parts-list-power-supply.html</a> - it has been working OK, but I was finding that it could be a bit slow getting the heat bed up to a stable temperature, especially if I want to print ABS (which needs a very hot heat-bed to stick properly). When I hooked up my multimeter, I found the supply voltage was dropping a bit under heavy load, so I guess my power supply really wasn't 100% up to its rated capacity. I started thinking about getting a proper desktop variable voltage power supply.<br />
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Luckily for me, JayCar recently had a special on several power supplies, including the MP-3800 <a href="http://www.jaycar.com.au/Power-Products-Electrical/Power-Supply/Laboratory-Bench/Compact-Switchmode-Laboratory-Power-Supply/p/MP3800">http://www.jaycar.com.au/Power-Products-Electrical/Power-Supply/Laboratory-Bench/Compact-Switchmode-Laboratory-Power-Supply/p/MP3800</a>, which they were offering for only AUD$119 (usually $149) - not bad for a 0-24 volt power supply, with a load rating of 15 amps continuous at 12 volts (18 amps peak). It is rated to better than 9 mV ripple voltage, and has thermal and overload protection, so it ticks all of my boxes.<br />
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Note that the rated output current capacity depends on the selected output voltage, so check your needs if you plan to run at other voltages:<br />
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So I grabbed one, hooked it up to my RepRap, and it works great - highly recommended!<br />
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The power supply has back-lit analogue gauges for volts and amps, which seem to be pretty accurate when I test against my multi-meter. The RepRap pulls a maximum load of about 12 amps during the heat-up phase, but this drops to around 5 - 6 amps during normal printing. The power supply handles this admirably, with no detectable fluctuation in supply voltage, even when the load is fluctuating rapidly, such as when the heat-bed is cycling on and off.<br />
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The voltage control knob has a central detent position, at which it delivers 13.2 volts, which is where I normally run the RepRap. (The RAMPS 1.4 card is nominally a 12 volt board, but it can happily take a little bit of over-voltage, and the extra supply voltage gives faster and more stable heat control.) However, I need to be sure to not accidentally overload the RAMPS by giving it 24 volts - I really wanted a digital display to give a crystal-clear voltage display, to make sure I don't over-power my RAMPS 1.4.<br />
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I bought a cheap 0-30 volt LED voltmeter on eBay for less than $3 including postage (search for <i>"0.36" LED Digital Voltmeter"</i>, and make sure to pick one which has the right voltage range for your power supply, as they come in 10V, 30V, 100V and 200V variants). Hook up the red and blue wires to the positive terminal and the black wire to the ground terminal, and you have a nice bright digital voltage display.<br />
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I then printed a voltmeter bracket which I came across on Thingiverse <a href="http://www.thingiverse.com/thing:239801">http://www.thingiverse.com/thing:239801</a>, and it works great - now I get a brilliant indication of supply voltage as soon as I power up, greatly reducing the risk of blowing the RAMPS electronics. (And of course it works just as well when I am using the power supply for my other electronics projects.)<br />
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<br />Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com2tag:blogger.com,1999:blog-108699730814653894.post-20762876121011996712015-09-10T09:06:00.001+10:002015-09-10T09:06:30.659+10:00Fantastic article on "Enchroma glasses, neuroscience, and the mystery of color"I just came across this article entitled <i>"What is color? Enchroma glasses, neuroscience, and the mystery of color"</i> by Blake Porter:<br />
<a href="http://www.blakeporterneuro.com/enchroma-neuroscience-color/">http://www.blakeporterneuro.com/enchroma-neuroscience-color/</a><br />
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It's a pretty lengthy piece, but well worth taking the time if you have an interest in how the human brain perceives colour, what colour blindness is, and how the EnChroma glasses work. You might also want to participate in his survey after you've read through the article:<br />
<a href="https://docs.google.com/forms/d/1VB4L7EQSkZ4M_IRrzjehXlMjToKTZcGQd3xKy3321cw/viewform">https://docs.google.com/forms/d/1VB4L7EQSkZ4M_IRrzjehXlMjToKTZcGQd3xKy3321cw/viewform</a><br />
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Porter's article explains the processes far more eloquently than I can. I've always been OK with Fire Engine Red, Canary Yellow, Sky Blue, and so on, but all of the intermediate and pastel colours have always been a problem, tending to blend into an undistinguished green-red-brown-pink-purple. Many colours that are dramatically different to most people are virtually indistinguishable for me.<br />
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The best description that I have been able to explain the EnChroma experience is like sitting in front of a well-adjusted colour TV, and then turning the “Colour / Saturation” settings up by about 25% – all the colours are “real”, but they become much more rich, vivid and saturated. Pastel shades which have very little colour intensity to my unaided eye now show much more saturation, with what were previously subtle differences between two shades now becoming much more distinguishable.<br />
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Green traffic lights are a good case in point – they've always looked white with a green tinge to my eye (like a fluorescent tube), but now they are definitely green. The other big “wow” factor for me is the sunset sky – I've always been vaguely aware of various shades of red, orange and pink at sunset, but they are generally very subtle and it’s only rarely bowled me over, but with the EnChroma lenses, every sunset is a delight! (I don’t know if this is what I've been missing my whole life, or of I'm seeing something that people with normal vision don’t see, but whatever it is, I really like it!)<br />
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But beyond the main EnChroma / Colour Blindness theme, there's some fascinating stuff about the impact of language and culture on our perception of colour. Did you know that the ancient Greeks didn't think the sky was blue? Or that there is a tribe in modern-day Namibia who can easily see the one square in the first pattern below which has a different shade of green (I sure can't), but struggle to see the blue square in the second pattern? Amazing stuff!<br />
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<br />Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-73787072321447642482015-09-02T09:51:00.001+10:002015-09-02T09:51:41.914+10:00More musings on EnChroma sunglasses for colour blindnessIt was a pretty big decision for me to go with the EnChroma sunglasses without having the opportunity of trying them first, but there are no dealers in Australia at present. However, I did a fair bit of research first, and took some comfort from the 30-day money-back guarantee (which I won't be using!)<br />
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I don't want to disparage other glasses which are advertised as enhancing colour blindness, as they may work well for many people, but I tried another brand a few years ago, and they didn't have a huge effect for me. (The EnChroma lenses are chalk and cheese in comparison for me). With respect to the technology aspect (narrow-band "notch" filters vs. "broadband" dye filters) - I don't know whether the benefits of narrow-band filters will apply equally to everyone, and I don't know whether any of the other brands are now using narrow-band filters - their website aren't always clear on the exact filter technology being used. <br />
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Narrow-band filters (as used in EnChroma) cut out a very specific "notch" of wavelengths (colours) while allowing very similar adjacent wavelengths to pass almost unaffected. Broadband dye filters (which is what the brand I tried previously USED to use, but I am not sure about now) generally suppress a range of colours, but then a have smooth "shoulder" of rising transparency for the adjacent colours that you want to pass - think of it as a sheer-edged canyon versus a smooth river valley.<br />
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If I make a rainbow spectrum with a glass prism and look at it with the EnChroma lenses, there are two distinct dark lines in it, one in the Blue end, and one in the Red-Green end. See this shot which I took (yes, I'm a science geek!) which shows the effect:<br />
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I expect to see the same effect on natural rainbows (but I haven't seen any since I got the glasses) - they will presumably split into three coloured bands with a narrow gap between them.<br />
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I think this is why the EnChroma lenses work so well for me - the Red-Green "notch" drives a "wedge" between my Red and Green receptors, allowing my eye to see colours in the Red-Green range as either predominantly Red or predominantly Green, but it does have the side-effect of making a few colours that span right across the "notch" a richer, darker colour (drab olive greens and khaki colours tend to become richer in hue but darker).<br />
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The broadband dye filters that I tried a couple of years ago don't have such a strong differentiating effect for me, but others may get a different effect (and they may have changed their lens technology in the last couple of years).<br />
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I think that the Blue notch in the narrowband EnChroma filter is not particularly "useful" for enhancing my colour perception (as I am Red-Green colour blind), but it is also why some digital displays get a green cast - if the peak wavelength of the Blue pixel in the RGB display falls right in the "notch", then the Blue signal is heavily suppressed, and White on an RGB display with very little Blue signal tends to come out greenish. So far, it seems that some (but not all) outdoor digital signs have this effect, and OLED computer / phone / tablet displays in particular seem to have the effect, but LED computer screens and TVs seem to be fine. My guess is that the Blue pixel in those outdoor signs and OLED displays happens to fall right in the "notch", but other display types have a different spread of Blue in their RGB mix, so plenty of Blue still gets past on each side of the "notch".<br />
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I suspect that the exact narrow-band filter "notches" that EnChroma use on their Cx-65 Indoor / Computer lenses may be tuned differently, to avoid excessive tinting on digital displays (but I haven't tried a pair to be certain).<br />
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I haven't noticed any "weirdness" from the Blue notch in general viewing of "natural" objects - the sky is still sky blue, but maybe some very specifically coloured blue flowers might darken significantly? (I'm looking forward to Jacaranda season as a good test - Jacaranda trees in flower are an intense vivid colour to my unaided eye; I'll be interested to see if they change with the EnChroma lenses.)Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-2093533770107060792015-08-26T15:24:00.003+10:002015-08-26T15:24:55.571+10:00So ... what does it actually LOOK like when you wear a pair of EnChroma sunglasses?That's a tricky question to answer, because when you think about it, you don't know what the world actually looks like through my eye's (or anyone else's), and I don't know how you perceive all the colours around you. The world looks "normal" to me, even though I perceive it differently to you.<br />
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I've been wearing the EnChroma sunglasses <a href="http://enchroma.com/">http://enchroma.com/</a> for a couple of days now, and the best overall description I can provide is to imagine turning the colour down on your TV or computer screen until it's black and white, and then bring it back up to 6/10 or 7/10 - that's sort of what the world looks to my unaided eye - the colours are all there, but they're all a bit muted and subdued.<br />
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(Actually, that's NOT how the world looks to me, but it's the best simulation I can think of!)<br />
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Now turn the colour back up to "normal" viewing (10/10), and then take it up to 11:<br />
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THAT'S roughly what the world looks like to me through EnChroma - everything becomes more saturated, and just "pops".<br />
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The effect is most noticeable on pastels and other unsaturated colours - they all become richer, denser and more saturated. If a particular shade has just a touch of red, or green or yellow, it will seemingly "boost" the colour to make it several shades "richer". You know how an external painted masonry wall will fade over time, and all your favourite shirts fade with multiple washes? It's like giving the wall a fresh coat of paint, or buying a new Hawaiian shirt.<br />
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Bright, saturated primary colours aren't affected nearly as much - but I can see most of them clearly anyway. Fire engines and mail boxes are still "signal red", the sky is still sky blue, Hi-Vis Safety Shirts are still canary yellow. But when you think about it, most of the colours in the world around us are a bit more subtle and muted than that, and it's these unsaturated colours which seem to get the strongest boost.<br />
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There were a few surprises as well:<br />
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Green traffic lights have always looked almost white to my eye, with only the slightest hint of colour - a bit like how "warm white" compact fluorescent bulbs look compared to the "cool white" ones - but now they are bright green. Also, for the first time ever, red traffic lights are brighter than amber traffic lights, whereas the amber has always been quite a bit brighter than the red to my eye.<br />
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The EnChroma lenses can give a strong green cast to some (but not all) digital displays – my SmartWatch and tablet are now green when they should be white (both have OLED screens), and there's an LED display board near my work which is now green, but my TV and phone look pretty normal (but a bit dark!), and as I sit at my computer typing this reply, the white is just white.<br />
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Interestingly, the blue LED status lights that you often see on electrical equipment seems to be a colour that my unaided eye sees very brightly, but the EnChroma lenses seem to block very strongly. I noticed it first on our TV Set-Top Box and a computer monitor at home, and also on the lift buttons at work. Even though the lift is well illuminated and I can see fine with the glasses on, the floor button back-lights almost disappear completely when I put the glasses on. I guess it depends on the exact colour spectrum of the RGB pixels - it would be interesting to see if this effect persists with the Cx-65 lenses, which are apparently optimised for digital screens and the like.<br />
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Drab greens and browns (I'm thinking of colours that you would probably describe as faded olive green or mission brown) become a LOT more dense, and therefore get quite a bit darker - again, it's a bit like over-painting a faded fence with new paint which is a couple of shades darker. I think these colours must lie pretty well in the red-green "notch" in the EnChroma transmission spectrum.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgQROaJf57sHK5YIvv_XktZkiCB0XfW_z6V3nnNQmJReawhKPg3QwBE7OaZ7LOtCXY-d4iAq9ZCcwqVDHGGfyM9aIRbevtq8aWqyb5JA7gxmLMa8IpY-8LV10sDjUZMha9cvwWeYQB-Wwo/s1600/How+EnChroma+Works.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="250" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgQROaJf57sHK5YIvv_XktZkiCB0XfW_z6V3nnNQmJReawhKPg3QwBE7OaZ7LOtCXY-d4iAq9ZCcwqVDHGGfyM9aIRbevtq8aWqyb5JA7gxmLMa8IpY-8LV10sDjUZMha9cvwWeYQB-Wwo/s320/How+EnChroma+Works.JPG" width="320" /></a></div>
<br />
I suspect things like army camouflage would be pretty strongly affected by this - but I haven't seen any army vehicles or personnel since I got the EnChromas. (Or maybe I did, but they disappeared totally against a dark background?)<br />
<br />
Anyway, that's enough of a report for now - I've got to get back outside to look at some more flower beds. (And look for that Jeep that I misplaced somewhere.)<br />
<br />
<br />Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-24660262891964504872015-08-25T20:29:00.000+10:002015-08-25T20:30:28.399+10:00Spectroscopy of EnChroma Cx 15 lenses I have taken a few spectroscopy images of the white light of a halogen bulb as viewed directly, and through a pair of normal (polarised) brown-tinted sunglasses, and through the EnChroma Cx 15 lenses.<br />
<div>
<br /></div>
<div>
Here's the direct halogen spectrum, unfiltered:</div>
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<br /></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiDJ76HCoTlGXL8F9_xak4ljFunWUzM-00PNj-HOunGQViPEqtq-kBIwENBAu1LrnMh4fGel16foncfBA0SCq-SJVvIUD9kHc9v3z_HwIisCOd4PRn_WRut6ulSmUEgk6MNs4kLZvoV4io/s1600/Direct+Halogen+Light.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="180" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiDJ76HCoTlGXL8F9_xak4ljFunWUzM-00PNj-HOunGQViPEqtq-kBIwENBAu1LrnMh4fGel16foncfBA0SCq-SJVvIUD9kHc9v3z_HwIisCOd4PRn_WRut6ulSmUEgk6MNs4kLZvoV4io/s320/Direct+Halogen+Light.jpg" width="320" /></a></div>
<div>
<br /></div>
<div>
(Ignore the streak on the left-hand side - the interesting bit is the rainbow on the right.) </div>
<div>
<br /></div>
<div>
This is the spectrum as seen through the normal sunglasses - you can see that they suppress all wavelengths more or less uniformly:</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgX2gfO9k_hFMzJftYEgOmHY8dd0FWmlwg4i4SoAbuzYPiAoH9cpSfPY4hNmoBPq-8SScX3hq_lUVXwZqQ2lsdrIa_jGqf9F0DGbLAGVqhlynKyR4gRJ32-KmttXs89NVfkQ7KUEuMYIJo/s1600/Normal+Sunglasses.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="180" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgX2gfO9k_hFMzJftYEgOmHY8dd0FWmlwg4i4SoAbuzYPiAoH9cpSfPY4hNmoBPq-8SScX3hq_lUVXwZqQ2lsdrIa_jGqf9F0DGbLAGVqhlynKyR4gRJ32-KmttXs89NVfkQ7KUEuMYIJo/s320/Normal+Sunglasses.jpg" width="320" /></a></div>
<div>
<br /></div>
<div>
And here's the view through the EnChroma lenses - you can see that they have two very distinct bands where virtually all light is blocked out, while other wavelengths pass with very little attenuation :</div>
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<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjahoNEH341OfCGDfAnPpr0deK3S03DR3NWsmgMy48aUOTGcwDxLy1t3ijtj_-qL3_dfn1l_XPosZy8Qt5DYGbKt068qT1-tRMyAjd_PY0Ub_oKs1Uzo855lYH4PlrpKr1TPL34KqaHeVk/s1600/EnChroma+Cx+15.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="180" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjahoNEH341OfCGDfAnPpr0deK3S03DR3NWsmgMy48aUOTGcwDxLy1t3ijtj_-qL3_dfn1l_XPosZy8Qt5DYGbKt068qT1-tRMyAjd_PY0Ub_oKs1Uzo855lYH4PlrpKr1TPL34KqaHeVk/s320/EnChroma+Cx+15.jpg" width="320" /></a></div>
<div>
<br /></div>
<div>
I've also shot a short video showing the effect - you should have no trouble working out when the normal sunglasses and the EnChroma lenses come between the light and the spectroscope:</div>
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<iframe allowfullscreen="" class="YOUTUBE-iframe-video" data-thumbnail-src="https://i.ytimg.com/vi/Df_b7dJ4f5s/0.jpg" frameborder="0" height="266" src="https://www.youtube.com/embed/Df_b7dJ4f5s?feature=player_embedded" width="320"></iframe></div>
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Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-22505740124934699672015-08-25T12:53:00.001+10:002015-08-25T12:53:12.249+10:00"Color for the Color Blind" - A quick review of EnChroma Sunglasses<div class="MsoNormal">
I'm severely Red-Green Colour Blind (technically, I have Deuteranomaly <a href="https://en.wikipedia.org/wiki/Color_blindness#Types">https://en.wikipedia.org/wiki/Color_blindness#Types</a>, a genetically transmitted condistion). </div>
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<br /></div>
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I’ve just acquired a pair of EnChroma Cx Explorer sunglasses, which are
designed to boost colour perception for many people who suffer from colour
blindness. (See <a href="http://enchroma.com/">http://enchroma.com/</a> ) </div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEipPLoo-orgjPe04q3dz2CekImXFx2SHgSBSZXugJ7Ba7zNMJjR7DRMNED5T_H-pmgt-Rn81qztzvNyFwYvgtCh_fwCyvd4m2rVdqSBav4vFUwWB27S_VRCCJyIDa4FULt2BaSrzuxibq4/s1600/EnChroma+Cx+Explorer.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="195" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEipPLoo-orgjPe04q3dz2CekImXFx2SHgSBSZXugJ7Ba7zNMJjR7DRMNED5T_H-pmgt-Rn81qztzvNyFwYvgtCh_fwCyvd4m2rVdqSBav4vFUwWB27S_VRCCJyIDa4FULt2BaSrzuxibq4/s320/EnChroma+Cx+Explorer.JPG" width="320" /></a></div>
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<br /></div>
<div class="MsoNormal">
The theory is that for people with normal vision, the Red receptors in the eye respond strongly to red, but only moderately to red-green colours, while the Green receptors respond strongly to green, but only moderately to red-green colours. For people with Red-Green colour blindness (which is my problem), the red and green receptors in the eye overlap in their colour reception, and both respond strongly to similar wavelengths in the red-green range, so they don't differentiate between red and green as well as a normal eye.</div>
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<br /></div>
<div class="MsoNormal">
The EnChroma lenses effectively transmit red and green, but largely block the intermediate red-green colours, so the red receptors will be triggered strongly by red but not by red-green (which are blocked by the lenses), while the green receptors will be triggered by green but not red-green. </div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjD6CRa3ONHp81aGktPPTJMSrAIQyp_tGlNkZzVrU7TP36IWybXUlRyFDfkCG2218WRHhiKsK7QWq2vAq2GJo_weJ9NDferODpZP0Rv4SOD2x4jm9zvFSqThYZigHf1NI18fqNs3tQRSRQ/s1600/How+EnChroma+Works.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="250" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjD6CRa3ONHp81aGktPPTJMSrAIQyp_tGlNkZzVrU7TP36IWybXUlRyFDfkCG2218WRHhiKsK7QWq2vAq2GJo_weJ9NDferODpZP0Rv4SOD2x4jm9zvFSqThYZigHf1NI18fqNs3tQRSRQ/s320/How+EnChroma+Works.JPG" width="320" /></a></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
Where these glasses differ from other products that I have seen advertised before is that these use narrow band-pass "notch" filters to cut out a very tightly defined band of red-green, whereas the more common type use pigmented dye filters, which filter out a wider and less clearly defined band of colours. </div>
<div class="MsoNormal">
<a href="http://enchroma.com/technology/">http://enchroma.com/technology/</a></div>
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<br /></div>
<div class="MsoNormal">
(The EnChroma lenses also have a "notch" for blue-green, which could be beneficial for some forms of colour-blindness, but is probably not so important for me - although maybe it helps with the overall effect as well?) </div>
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<br /></div>
<div class="MsoNormal">
My
pair arrived yesterday.</div>
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<br /></div>
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So - do they work? In a word: <o:p></o:p></div>
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<br /></div>
<div class="MsoNormal">
<b><u>YES!<o:p></o:p></u></b></div>
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<br /></div>
<div class="MsoNormal">
They're quite dark (just 14% overall light transmission), so
they're intended for full daylight use, not really suited for indoor use. If you're wondering - 14% transmission is pretty typical for a sunglass lens designed for full sunlight. E.g. Oakley provide a range of tints from 9% to 11% for "Extremely bright light", while 13% to 22% are rated for "Medium to bright light".</div>
<div class="MsoNormal">
<a href="http://www.evo.com/oakley-sunglasses-lens-tint-guide.aspx">http://www.evo.com/oakley-sunglasses-lens-tint-guide.aspx</a></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
EnChroma offers three lens shades: 14% for "strong daylight", 25% for "medium-to-low light outdoor conditions" and brightly-lit indoor use, and 65% for general indoor / computer use. The 14% has the strongest colour-correcting effect, which is why I chose it.</div>
<div class="MsoNormal">
<a href="http://enchroma.com/cx-lens-guide/">http://enchroma.com/cx-lens-guide/</a></div>
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<br /></div>
<div class="MsoNormal">
In muted
light this morning (7:30 am, a bit of light cloud / mist), the effect outdoors was
obvious - a lot more contrast and definition between various shades of green
and red in the garden.</div>
<div class="MsoNormal">
<o:p></o:p></div>
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<br /></div>
<div class="MsoNormal">
But as the sun broke through - WOW!<o:p></o:p></div>
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<br /></div>
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Colours became quite eye-popping - our dry winter lawn
became a vivid green, pastel flowers that always faded into the background
suddenly stood out ...<o:p></o:p></div>
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<br /></div>
<div class="MsoNormal">
The most dramatic difference was driving in to work - so,
green traffic lights are actually green? Who knew?! <span style="font-family: Wingdings;">J</span><o:p></o:p></div>
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<br /></div>
<div class="MsoNormal">
(Green traffic lights have always looked almost white to my
eye, with only the slightest hint of colour, but now they are bright green.
Also, for the first time ever, red traffic lights are brighter than amber
traffic lights, whereas the amber has always been quite a bit brighter than the
red to my eye.)<o:p></o:p></div>
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<br /></div>
<div class="MsoNormal">
Some unexpected effects - they can give a strong green cast
to some (but not all) digital displays - my Android tablet is now green when it
should be white, but my phone looks normal. There's an LED display board
outside the Convention Centre which is now green, but as I sit at my computer
typing this, the white background is just white. I guess it depends on the
exact colour spectrum of the pixels.<o:p></o:p></div>
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<br /></div>
<div class="MsoNormal">
I'll by trying to catch a spectrum tonight using my Public Lab Spectrometer <a href="http://publiclab.org/wiki/spectrometer">http://publiclab.org/wiki/spectrometer</a> - I'm expecting to pick up a couple of strong "notches" in the white light spectrum. I'll post here when I've captured a useful spectrum.</div>
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<br /></div>
<br />
<div class="MsoNormal">
(For the sceptics: There is some “real science” behind these
glasses, which differentiates them from other tinted sunglasses which have been
promoted as "cures" for colour blindness – e.g. see: </div>
<div class="MsoNormal">
<a href="http://www.smithsonianmag.com/innovation/scientist-accidentally-developed-sunglasses-that-could-correct-color-blindness-180954456/?no-ist">http://www.smithsonianmag.com/innovation/scientist-accidentally-developed-sunglasses-that-could-correct-color-blindness-180954456/?no-ist</a> )</div>
<div class="MsoNormal">
<br /></div>
Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-8624775912038611542015-08-14T11:00:00.000+10:002015-08-14T11:04:46.192+10:00Affordable (Free!) 3D Modelling Software - A 5-Minute ReviewWhen I started my adventures in the 3D printing world, I was using Alibre Design <a href="http://www.alibre.com/">http://www.alibre.com/</a> as my main 3D modelling software. While I still have a valid Alibre licence, they have been taken over by 3D Systems (as you will see straight away if you click on the Alibre link above), and the software has morphed into "Geomagic Design", which has different features and licensing terms, and it has been increasingly difficult to migrate my Alibre licences onto new computers, running new operating systems. I thought it was time to look for a new CAD modelling software system to generate designs to feed my 3D printer.<br />
<br />
There are many, many free and low-cost 3D modelling software options available, so where to start? Well, a good place is to list my must-haves and nice-to-have features:<br />
<h4>
Must-Have:</h4>
<ul>
<li>I am looking for something that will design "mechanical" components, rather than "free-form" modelling (i.e. a mechanical CAD system (MCAD), rather than an artistic "clay modeller")</li>
<li>Parametric modelling - e.g. the ability to edit a dimension and have the model "rebuild" itself (e.g. change the size and spacing of a group of bolt holes) </li>
<li>True "solid modelling", not "surface modelling" capabilities - e.g. I need to be able to insert a hole or cut-away, and have the internal volume recognised as a solid rather than a void</li>
<li>Precision modelling capabilities - I need to be able to model to a fraction of a millimetre (even if my 3D printer's precision / tolerance are not quite up to the task sometimes!)</li>
<li>Familiar UI layout / functionality / workflow - I have used various MCAD software such as Alibre, Solidworks, etc for many years, and their UI and general functionality suits me, and I don't see any need to lean a completely new way of working to achieve the same goals; I realise I will need to learn new icons and menus etc, but I am looking for the same overall workflow concepts such as Create a Sketch / Extrude / Fillet / etc</li>
<li>Runs on Windows 10 (all of my home Windows machines have now been upgraded to Windows 10)</li>
<li>Exports models in STL format</li>
<li>100% legal for personal / hobby use - I've been down the pirate software option, and I've used "extended trials" and "student licences" and so on, but I want to "keep it clean" from now on</li>
</ul>
<h4>
Nice-To-Have:</h4>
<ul>
<li>Import / Export a variety of industry-standard CAD formats (e.g. IGES, STEP, etc)</li>
<li>Assembly Modelling (build assembles of multiple parts, to check fit and interference, etc)</li>
<li>Runs on other platforms (e.g. Chromebook, Android tablet, etc)</li>
<li>Will run without needing to "install" any software (I don't mind "installing" software on my own computers, but work policies prohibit the installation of software on the company's computers)</li>
<li>Legal for limited work-related use (I would sometimes like the ability to create simple models for finite element analysis )</li>
</ul>
<div>
Alibre Design still works very well for me, apart from the licensing / migration issues, so it's time for me to move on. SketchUp <a href="http://www.sketchup.com/">http://www.sketchup.com/</a> doesn't quite cut-it - it's a terrific package for what it does, but it falls short on the precision MCAD capabilities. After doing an exhaustive search (i.e. a few quick Googles), here's what I came up with for closer consideration:</div>
<div>
<br /></div>
<h2>
Onshape</h2>
<div>
<a href="https://www.onshape.com/">https://www.onshape.com/</a></div>
<div>
<br /></div>
Onshape advertises itself as <i>"the first and only full-cloud 3D CAD system that lets everyone</i><br />
<div>
<div class="separator" style="clear: both; text-align: center;">
</div>
<div>
<i>on a design team simultaneously work together using a web browser, phone or tablet"</i> - and it seems to be true. Forget what you might think about Cloud software, and how slow it surely must be - Onshape has a pretty full set of professional modelling tools, and runs really well in a browser on even modest hardware such as a Chromebook, and it has native apps for iPad and Android tablets.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj1GHfbZEt1ZcuH9xMDU4oPUmz3sqk5_EhmKpa5zooJJEV6i9MAJbZXh-Q6ZMCyClO28VZ6DTPJy9W38qj6A0PrRu3nHu-EgOKEgW1NhlQ5_q5x923DHUg91igMwLTUTNWn3dDdY7s9Yfo/s1600/OnShape+in+Chrome+Browser.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="201" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj1GHfbZEt1ZcuH9xMDU4oPUmz3sqk5_EhmKpa5zooJJEV6i9MAJbZXh-Q6ZMCyClO28VZ6DTPJy9W38qj6A0PrRu3nHu-EgOKEgW1NhlQ5_q5x923DHUg91igMwLTUTNWn3dDdY7s9Yfo/s320/OnShape+in+Chrome+Browser.png" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Onshape running in Chrome browser on Windows PC<br />
<br /></td></tr>
</tbody></table>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjmtqAWnjckk9h2-M_r9horLM6ueSlzD3yQ2ooxR0VHUZDVYLCjgIunzEKZshWk_mZTQMSCiqn_hbzUGP-pRGrDcAP2NmhSd7GCViTMKtjkR7f4ju0QDClzvRlekfsZmtlTbKR23vjqFBQ/s1600/Onshape+app+on+Android+tablet.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjmtqAWnjckk9h2-M_r9horLM6ueSlzD3yQ2ooxR0VHUZDVYLCjgIunzEKZshWk_mZTQMSCiqn_hbzUGP-pRGrDcAP2NmhSd7GCViTMKtjkR7f4ju0QDClzvRlekfsZmtlTbKR23vjqFBQ/s320/Onshape+app+on+Android+tablet.png" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Native Onshape app on Android tablet </td></tr>
</tbody></table>
<br /></div>
<div>
Capabilities include a wide range of import / export formats, assembly modelling, and so on. It's missing a few high-end features, but it is still undergoing active development (automatic 2D drawing generation is coming soon, for example).</div>
</div>
<div>
<br /></div>
<div>
The software designers come from the team that developed SolidWorks, and it shows in the toolset and UI design - if you have previous experience with professional MCAD software, you will feel at home very quickly.</div>
<div>
<br /></div>
<div>
What is truly remarkable, is that all of this capability is available free for hobby / personal use: <a href="https://www.onshape.com/features-and-pricing">https://www.onshape.com/features-and-pricing</a></div>
<br />
<div>
You get access to ALL of the modelling tools for free - the only real limitation for the free account is the amount of Cloud storage space (5 GB for free accounts vs 100 GB for paid "Professional" accounts) - being a Cloud-based system, all of your models HAVE to reside on the Onshape cloud-store, but you can export models to your own file storage. 5 GB should be ample for all but the most ardent hobby modellers, though. In addition, you are limited to having 5 concurrent "Active" documents open at a time. For most hobby users, this won't be an issue - there is no limit on the total number of models you can have, but you may need to toggle some of them to be "Inactive" to free-up a new "Active" model. (Note that a "Document" can be a full assembly, with all of its parts, so you can have a lot of "Active" content at any one time!)</div>
<div>
<br /></div>
<div>
My only real reservation is that being proprietary software, there is always a chance that the owners might decide to abandon the free personal licence model at some future date, leaving me without free access to my models. However, their FAQ <a href="https://www.onshape.com/faqs">https://www.onshape.com/faqs </a>suggests that there is no intention for this to happen, so I'll give them the benefit of the doubt:</div>
<br />
<div class="faq-question" style="box-sizing: border-box; color: #4b4b4b; font-family: flama-light, sans-serif; font-size: 1.3em; line-height: 20px; padding: 12px;">
<i><span style="box-sizing: border-box; font-family: flama-bold, sans-serif;">Q: </span> Will Onshape ever change or restrict the Free plan?</i></div>
<div>
<div class="faq-answer" style="box-sizing: border-box; color: #7b7b7b; font-family: flama-light, sans-serif; font-size: 16px; line-height: 20px; padding: 12px;">
<i><span style="box-sizing: border-box; font-family: flama-bold, sans-serif;">A: </span> Although we cannot guarantee that there will never be additional differences between the Free and Professional plans, we expect that CAD modeling, drawings, and data management capabilities will continue to be fully available under the Free plan.</i></div>
</div>
<br />
<div>
All in all, if you are looking for a good 3D modelling capability, you HAVE to take a look at Onshape!</div>
<h2>
FreeCAD</h2>
<div>
<a href="http://www.freecadweb.org/">http://www.freecadweb.org/</a></div>
<div>
<br /></div>
<div>
FreeCAD is a totally free, open-source 3D parametric modeller. It seems to be the best-developed open-source 3D MCAD modelling software I have come across, and it is still being actively developed and supported. As such, it has a large user community, and it is likely to be around for a long time to meet your needs. It is available on Windows, Linux and Mac, so will work for most PC users (but no Chromebook or mobile app as yet).</div>
<div>
<br /></div>
<div>
It's part-modelling capabilities arr pretty comprehensive (certainly adequate for my needs), and being open-source (with support for Python scripting), it has plug-ins / add-ons / extensions for a range of other software systems, such as Assemblies, 2D drawings, rendering, BIM / IFC, etc.<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEvhNWtmg1LFu6dS5dMG7274iC4jmT6skot4fTvfLa4cyjwpAPd7hQpx_Y52VR7h16aoxAHMfT63vu6G_ix4x-120iT3-YnME7p5MLG_yGi3G1nl5fGZdeL0TuyY47mp-CzAdrzRB5vkY/s1600/1024px-Freecad_jeep.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="193" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEvhNWtmg1LFu6dS5dMG7274iC4jmT6skot4fTvfLa4cyjwpAPd7hQpx_Y52VR7h16aoxAHMfT63vu6G_ix4x-120iT3-YnME7p5MLG_yGi3G1nl5fGZdeL0TuyY47mp-CzAdrzRB5vkY/s320/1024px-Freecad_jeep.png" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">FreeCAD on Windows PC</td></tr>
</tbody></table>
<br /></div>
<div>
In all honesty, I would have been perfectly happy with FreeCAD if it wasn't for the fact that it needs to be "installed" on Windows computers, which my work will not permit. I was looking for something that I could access occasionally at work, which is how I came across the cloud-based browser-accessible Onshape. However, if you're looking for 100% free, open-source 3D MCAD software, FreeCAD seems to be the pick of the bunch for now.</div>
<h2>
AutoDesk Fusion 360</h2>
<div>
<a href="http://www.autodesk.com/products/fusion-360/overview">http://www.autodesk.com/products/fusion-360/overview</a></div>
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<div>
The AutoDesk brand should need no introduction, but Fusion 360 might not be familiar to you. Basically, Fusion 360 is a professional-quality cloud-based 3D CAD/CAM tool, which supports both Mechanical and Free-form modelling. If you're familiar with Inventor, then you will understand Fusion 360. While it is a cloud-based service, it does require an application to be installed on your PC (Windows and Mac are supported) - it does NOT run in the browser, so other platforms (Linux, Chromebook, mobile, etc) are nor currently available options.<br />
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh9sKoyWYWGK4Z3CLGEdcmIbkaToCZkcQ5LWo2YRHKEX93zg3YtB3-N9dn7d23h02-sJTzEtZPFBbTL76GI9V54XGXJlTOHBfpqy11kVLGokq5sOGuZSiqW_tyyLtQtBPIj-N0FcM-EYE8/s1600/Fusion+360+Capture.JPG" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="180" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh9sKoyWYWGK4Z3CLGEdcmIbkaToCZkcQ5LWo2YRHKEX93zg3YtB3-N9dn7d23h02-sJTzEtZPFBbTL76GI9V54XGXJlTOHBfpqy11kVLGokq5sOGuZSiqW_tyyLtQtBPIj-N0FcM-EYE8/s320/Fusion+360+Capture.JPG" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fusion 360 UI on PC</td></tr>
</tbody></table>
<br /></div>
<div>
The licensing model is rather unusual. AutoDesk has long offered free or very low-cost Student Licences, as long as you have a valid student ID, but these would expire after some period, and you would then be "strongly encouraged" to upgrade to a full licence. Fusion 360 is different:</div>
<div>
<br /></div>
<div>
As well as the traditional free 3-year Student licence, AutoDesk offers <a href="http://www.autodesk.com/products/fusion-360/try-buy">http://www.autodesk.com/products/fusion-360/try-buy</a> a free 1-year "start-up license" for <i>"hobbyists, enthusiasts, makers, and emerging businesses that make less than US$100,000 in revenue per year"</i>. At the end of the 1-year term, you can reselect the start-up entitlement as often as you want (and as long as AutoDesk continues to support this licensing model). </div>
<div>
<br /></div>
<div>
If you are familiar with AutoDesk products (especially Inventor), and especially if you want 100% compatibility with an AutoDesk work environment for example, then Fusion 360 is well worth a look. If you don't have a history with Inventor and other AutoDesk products, you might find it a bit more than you need, but then you only need to learn how to use those parts of its comprehensive tool-set that interest you. Going with an AutoDesk product has the advantage that there is a huge global Inventor user-base, and you can pick up any number of "How To" books from your local book-store (most of which should also apply to Fusion 360), so getting training and support is a no-brainer. </div>
<div>
<br /></div>
<div>
And since it's free and legal (for now, anyway), why not give it a try if your interest is piqued?</div>
<h2>
And the winner is ......</h2>
<div>
Well, for now, it's almost a dead-heat. </div>
<div>
<br /></div>
<div>
I really, really like Onshape - it works well, offers ALL of the features I'm interested in, and is truly multi-platform. My only qualifiers are the fact that it is Cloud-based (so won't work without an Internet connection) if that worries you, and the fact that it is proprietary software, and they might change their personal / hobbyist licensing terms one day. (I'll probably keep using it as long as it's free). In my view, Cloud-based software is probably the way of the future, and I have access to an Internet connection almost all of the time. The ability to view / refine models on any device at any time is a real plus (e.g. put the finishing touches on a design using your tablet while you're on the bus home after work). </div>
<div>
<br /></div>
<div>
Otherwise, FreeCAD will also stay in my portfolio - partly because it's very good, and partly as a back-up in the event that Onshape is no longer available to me. It does MOST of what I want, but it isn't quite as polished, and it won't run on all of my devices (I can't install it on my work computer or my Chromebook, and I can't access it on my Android tablet, for example).</div>
<div>
<br /></div>
<div>
In third place for me is Fusion 360 - but mainly because it's a bit of a sledgehammer to crack a walnut as far as my needs are concerned - but if you have a track record with AutoDesk software generally (and Inventor in particular), you may well want to take a look.</div>
<div>
<br /></div>
<div>
For now, I'll give a Points Decision to Onshape - I'll post an update after a few months use to let you know if my feelings have changed.</div>
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Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-83966189667683139862015-07-30T08:47:00.003+10:002015-07-30T08:47:53.911+10:00Interested in getting into 3D printing, but don’t want to spend a lot?<div class="MsoNormal">
<span style="color: #1f497d;">How about AU$246.28 (plus postage) for a fully
assembled, ready-to-go machine?</span></div>
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<span style="color: #1f497d;">The TinyBoy Mini 3D Printer is a fully assembled machine designed by Parker Leung of Tiny Boy <a href="https://github.com/HKCOTA/TinyBoy">https://github.com/HKCOTA/TinyBoy</a> as an open design easy to use 3D printer.</span><span style="color: #1f497d;">The Mini Fabrikator by TinyBoy was designed around a concept that by 2016 every student should have the opportunity to have a 3D printer on their desk.</span></div>
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<span style="color: #1f497d;">The TinyBoy is available on-line from HobbyKing for only AU$246.28 (at the time of writing): </span><a href="http://www.hobbyking.com/hobbyking/store/__80708__Mini_Fabrikator_3D_Printer_by_Tiny_Boy_Transparent_AU_230V.html" style="color: #1f497d;">http://www.hobbyking.com/hobbyking/store/__80708__Mini_Fabrikator_3D_Printer_by_Tiny_Boy_Transparent_AU_230V.html</a><span style="color: #1f497d;"> </span></div>
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<span style="color: #1f497d;"><br /></span></div>
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<span style="color: #1f497d;">(Postage is extra, and ranges from AU$82 to AU$169 for delivery to Australia.)</span></div>
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<span style="color: #1f497d;">The machine is only 150 mm x 150 mm x 220 mm, and the build volume is fairly small (80 mm x 80 mm x 80 mm) so it can only make small components.- but still, at that price, why wouldn't you buy one?</span></div>
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Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-78028129554937606432015-05-28T13:36:00.002+10:002015-05-28T13:39:29.483+10:00Some more night-sky time-lapses with ZWO ASI120MC cameraMy ZWO ASI120MC astro-camera <a href="http://julianh72.blogspot.com.au/2014/09/zwo-asi120mc-planetary-camera-quick.html">Quick Review</a> shipped with a 2.1 mm 150-degree fish-eye lens, which is good for doing "almost-all-sky" video / time-lapse photography pointing straight up. It has the dynamic range needed to be able to shoot both day-time and night-time skies.<br />
<br />
It will also take other standard CS-mount CCTV lenses. I bought a 6 mm - 15 mm zoom lens for $20 on eBay, which is good for wide-field shooting when the camera is mounted "piggy-back" onto my telescope, or mounted on a tripod. <br />
<br />
Here are a few night-time time-lapse videos which I shot to give a sense of what it can do.<br />
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<br />
The first video is a time-lapse of the "All-sky" view looking straight up with the 2.1 mm fish-eye lens (150 degree horizontal FoV). The video was shot using 5-second frame exposures, set to default 50% Gain, for 210 seconds of actual elapsed time. (Video shot at 8:39 pm 27 May 2015 in Brisbane; showing a very over-exposed Moon in the top right, and the Southern Cross and Pointers in bottom-centre of view.) Note: This sequence looks quite dark when viewed in a "window" on this page, but you can see more detail if you go full-screen.<br />
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Next comes a time-lapse looking almost due south, again with the 2.1 mm lens, using 30-second exposures <complete id="goog_1537523025">@</complete> 50% Gain, for 400 seconds actual elapsed time. (Shot at 8:52 pm 27 May 2015 in Brisbane; over-exposed Moon in top right; centred on Southern Cross and Pointers.) You can see a lot more stars and nebulosity with the longer frame exposures - e.g. hints of Eta Carinae and the Running Chicken.<br />
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Finally, here is a time-lapse looking south with the 15 mm CCTV lens, using 30-second exposures @ 50% Gain, for 600 seconds actual elapsed time. (Shot at 9:23 pm 27 May 2015 in Brisbane; centred on Southern Cross and Pointers.) The background sky is very light with this sequence, so I would probably get better results if I tweak the exposure settings; and I'm not sure that I got the focus quite right. Still, the amount of detail and faintness of the resolved stars isn't bad.<br />
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<br />Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-2750051015036559552015-05-28T11:14:00.002+10:002015-05-28T11:15:24.174+10:00How to buy a second-hand telescope<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">So … you’re interested in getting into backyard astronomy, and you’re thinking of buying a second-hand telescope - where do you start? Used telescopes come up for sale all the time on eBay, GumTree, garage sales, second-hand dealers, etc, as well as on Astronomical forums such as Ice In Space </span><a href="http://www.iceinspace.com.au/forum/forumdisplay.php?f=27" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.iceinspace.com.au/forum/forumdisplay.php?f=27</span></a><span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> and Australia Astronomy Buy and Sell </span><a href="http://www.astrobuysell.com/au/index.php" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.astrobuysell.com/au/index.php</span></a><span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> . Many of these telescopes were bought by other novices (just like you!) who bought a telescope and then discovered they didn't have the knowledge or interest to sustain the hobby - you can benefit from their mistake by buying a telescope at half the recommended retail price or less, but you need to be able to pick the gems from the junk.</span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><br /><span style="vertical-align: baseline;">How does a novice go about evaluating a used telescope to decide whether to buy?</span></span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><br /></span></div>
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Do you have any experience with telescopes, or do you have a friend who has some knowledge? It is a LOT easier to buy a used telescope with confidence if you know what to look for. If you have no prior experience with telescopes, you may have no way of knowing whether the telescope which is offered for sale is any good at all, or is in fact a complete dog. I am not going to offer you any tips for how to judge the quality of a telescope other than by looking through it and assessing the quality of the image, which is ultimately the only thing that really matters. </span></div>
<b id="docs-internal-guid-b7eddc47-980e-0651-8375-45632ee42a0c" style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">If you don't have any experience with telescopes, and can’t inspect with a friend with some experience, the following tips may not make much sense.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">First and foremost, do your research so that you know what sort of telescope you are looking for, and the relative strengths and weaknesses of each type. Do you want a long focal length (high magnification) or short focal length (wide angle) telescope? Do you want maximum aperture or maximum portability? Will the telescope be used mainly for visual or photographic use? Do you want a GoTo mount, or will manual pointing be OK? A lot of second-hand telescopes are on the market because the owners simply don’t know how to use them, so you may not get much useful advice from the seller.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Note that there is no single “best” telescope, they all have their strengths and weaknesses, and buying any telescope is therefore a compromise. There is a truism that “the best telescope is the one that you use the most”, so think about where you will store it, where you will use it, and how you will move it around. </span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">A big Dob will give jaw-dropping views of deep-sky targets, but can be cumbersome to store and move; a modest refractor or Cassegrain (80 mm - 150 mm aperture say) on a computerised GoTo mount can be a much more portable instrument, but will lack the light gathering power of a big Dob. Intermediate sized Schmidt-Cassegrains (200mm - 250mm aperture say) are considered to be wonderful all-rounders, but are relatively expensive. If you succumb to the backyard astronomy bug, it is inevitable that you will contract Aperture Fever, and you will be on an endless pursuit for bigger and better telescopes. I would suggest that a first-timer should consider a quality instrument which is convenient and portable as a first telescope, as it is likely to be used more often than a big heavy cumbersome “light bucket”.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">If possible, I take a couple of my best eyepieces with me for the inspection, a 10mm - 20mm diameter chrome ball bearing (which I’ll explain below), and a torch. A lot of used telescopes are sold with only one or sometimes no eyepieces, and it is pretty hard to judge the condition if you can’t look through the telescope! Sometimes, the eyepieces that come with entry-level telescopes are quite ordinary quality, and a decent eyepiece will show the telescope to its best advantage. I would take a good wide-field 10mm and 25mm eyepiece (or thereabouts), and possibly a 6mm and a 32mm as well.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">I prefer to inspect in daylight hours if possible, because it's a lot easier to judge the condition in good light, and you can get a good feel for the optical quality by looking at a distant building or tree. For astronomical use, the ultimate test is a star test, and if I was spending a lot of money, I would want to do a night-time inspection before sealing the deal, if possible. However, Murphy’s Law will probably conspire to make it cloudy when your dream telescope is offered for sale, and you won’t want to let it slip away. A star test can be simulated in full sunlight by putting a chrome ball bearing in the sun about 20 metres away and pointing the telescope at it. The image of the sun on the ball bearing should be a brilliant pin-point of light, which simulates a star in broad daylight. If it is cloudy, or at night, shine the torch on the ball bearing to create an artificial star image.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Ultimately, as long as the optics are good, the telescope should be usable. I wouldn't buy a telescope with poor optical quality unless it is to get parts for tinkering - if you don't have good knowledge and technique, it can be very difficult if not impossible to get a good image from a telescope with dirty misaligned mirrors and lenses.</span></div>
<b style="font-weight: normal;"><br /></b>
<br />
<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">A little bit of dust on the outside of a refractor or Cassegrain, or on the primary and secondary mirror of a Newtonian, is not necessarily a big problem, but I would walk away from any telescope which has a lot of dust inside the closed tube of a reflector or Cassegrain, or any telescope with a lot of fungus on any of the optical elements. I would also avoid any telescope which shows a lot scratches on the lenses and mirrors. It is possible to clean dust and even fungus from lenses and mirrors, but they are also easy to damage if you’re not careful. It’s very important that you can re-assemble the telescope precisely aligned if it needs to be pulled apart for cleaning and refurbishment, so don't think about undertaking this unless you have done your research first.</span></div>
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<div dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">If the telescope is clean and tidy on the outside, that indicates the optical quality is PROBABLY in fair to good condition, but check anyway. Shine a bright torch down the tube, to see how clean all the elements are. A little bit of dust is not a big problem, but thick films of dust or other gunk are something to be wary of. I’m not too worried if the outside of the telescope tube and mount have a bit of dust and even light rust (especially for an older telescope), but very poor external quality is again a sign that the telescope has not been cared for, and this could affect the optical quality as well.</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">If the telescope looks OK, set it up to point at a distant target (a tree or building on the horizon is ideal), and check out the image. Note that if it is a warm day in particular, the air will shimmer from thermal currents, and the image will wobble. Try to avoid pointing over hot surfaces such as roads, building roofs etc, as these tend to generate the strongest thermal currents. A distant target over trees will generally give a more stable image than over building roofs and roads, but of course, you will be limited by the situation where the telescope is offered for sale.</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">How does the image look - crisp and sharp from edge to edge, or is it blurry and hard to focus? If the general image looks OK, I would then use my ball bearing “artificial star” as the final test - you should see a brilliant pin-point when it is in focus, and this should turn into a nice-round donut with a black hole when you focus slightly in and out. If you can’t get a nice pin-point in focus, and nice donuts when slightly out of focus, this indicates an issue with the alignment of the optical elements (collimation). Unless you know how to collimate a telescope, I would walk away at that point. Collimation is quite easy for some telescope types (Newtonians and Schmidt-Cassegrains) as long as it is not too far out of alignment to start with, but much harder on refractors and Maks). If you know what you’re doing, you might even be able to collimate it on the spot, but if it’s badly out of collimation and you don't know what you’re doing, walk away.</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Assuming the telescope comes on a mount, how does it feel - is it smooth and easy to balance, or does it grab and jerk as you move it? Does it hold position firmly when you find a target, or does it slip and droop? There is nothing more frustrating than trying to go stargazing on a mount which won't let you find and hold targets!</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">If it is a powered mount, does it work properly? Again, a lot of used telescopes are sold by people who have no idea how the powered mount should operate, so it is worth checking before you go whether they know how to power it, whether it has batteries, etc. If they don't know, it will be difficult to test the mount unless you are familiar with how that type works, and can bring along a suitable power supply to test it. It can be tricky to fully test a computerised GoTo mount in daylight hours, but as long as you can get power to the two drives, and move it left and right, and up and down, there is a good chance that the mount is more or less fully functional.</span></div>
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<span style="font-family: Arial; font-size: 15px; vertical-align: baseline; white-space: pre-wrap;">If the mount is in very poor condition (or missing altogether), most telescopes can be mounted onto any standard mount, so you can consider buying the telescope for the optical tube alone, and budget for a separate mount.</span>Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-37523965976196483522015-01-14T11:34:00.000+10:002015-01-14T11:41:00.096+10:00Samsung Gear Live & Android Wear - A Quick Review<div dir="ltr" style="line-height: 1.15; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">As a lover of all kinds of techie toys, I’ve been intrigued by the idea of smartwatches since they were first introduced. I even bought a first-generation Sony SmartWatch when they were being heavily discounted not long after they were first introduced in 2011/12. It worked fine (indeed, it still does), but it’s pretty limited in what it can do. It was an interesting concept, but it clearly needed a lot of work, and it didn't take me long to work out why the first-generation smartwatches never really captured the world’s imagination.</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">But move along to late 2014 / early 2015 (a couple of years is a couple of generations when it comes to consumer electronics!), and Google’s announcement of Android Wear </span><a href="http://www.android.com/wear/" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.android.com/wear/</span></a><span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> (and of course Apple’s pre-announcement of the as-yet vapour-ware Apple Watch </span><a href="http://www.apple.com/au/watch/?cid=wwa-au-kwg-watch-com" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.apple.com/au/watch/?cid=wwa-au-kwg-watch-com</span></a><span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> )</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Now </span><span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: bold; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">THIS</span><span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> has the potential to really change things - the two biggest names in mobiles getting seriously behind the whole concept of “wearables” and smartwatches.</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">In Australia right now (January 2015), there are only three Android Wear watches officially available through the Google Play store <a href="https://play.google.com/store/devices/collection/promotion_5000135_android_wear_au">https://play.google.com/store/devices/collection/promotion_5000135_android_wear_au</a> - the LG G Watch (Google Play price AU$249) and G Watch R (AU$349), and the Samsung Gear Live (AU$250). The Moto 360, Sony SmartWatch 3 and Asus ZenWatch are not on sale through the Google Play store or most mainstream retail outlets yet (although I believe you can get the Moto 360 in a few shops, if you know where to find them). </span></div>
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<a href="http://www.officeworks.com.au/shop/officeworks/samsung-gear-live-black-sgearliveb?searchTerm=samsung%20gear%20live" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">http://www.officeworks.com.au/shop/officeworks/samsung-gear-live-black-sgearliveb?searchTerm=samsung%20gear%20live</span></a></div>
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<span style="font-family: Arial; font-size: 15px; line-height: 1.15; white-space: pre-wrap;">This was the one I had been looking at anyway, as it adds a heart-rate monitor to the sensors available on the cheaper of the two LG watches. Naturally, I hot-footed it to my nearest OfficeWorks, but couldn't see them anywhere. When I asked at the counter - yes, they had them (plenty of them) in a locked cabinet behind the counter, but none on display. (So I guess the reason OfficeWorks have dropped the price is because they aren't selling many - and the reason they aren't selling many is because they hide them from view, and you have to ask to even be aware that they have them.)</span><br />
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">I got it home, charged it and paired it to my Nexus 4 (running stock Android 5 Lollipop), and it all worked seamlessly. The first thing it did after pairing was to upgrade its own firmware – and a few days later, it did so again - it now reports that it is running Software version 5.0.1.</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">I have to say this thing is about a hundred light years ahead of my previous smart-watch (1st Gen Sony SmartWatch), for not much more than I paid for the Sony – both in build quality, and functionality and features. I suspect that's at least partly because the Android Wear platform is so much more "mature" and capable than the limited functionality that the Sony could offer a couple of years ago, but of course the hardware has moved on a lot in 2 years as well. I love the integration to all of my stock Android apps. (Did you know that when you start the Camera app on your phone, you get a remote release button that automatically pops up on the phone? Neat – but I'm not sure when I'll ever use it!)</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">First impressions: </span></h2>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The watch fits comfortably, and even though it’s quite big physically, I don’t notice it once its on. (My “real” watch is a Tag-Heuer diver’s chronograph, so I’m quite used to a big watch - the Samsung is comparable in physical size, but a lot lighter.) I don’t have any problems with the strap fastening system that some people complain about (pins that plug into holes, rather than a conventional clasp or buckle ), and it hasn’t once threatened to come undone.</span></div>
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<a href="http://3.bp.blogspot.com/-QoLBYBuNgE0/VLXF7AnKM_I/AAAAAAAAHRU/FyAjpsuzNno/s1600/Samsung%2BGear%2BLive%2B-%2Bside%2Bview.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://3.bp.blogspot.com/-QoLBYBuNgE0/VLXF7AnKM_I/AAAAAAAAHRU/FyAjpsuzNno/s1600/Samsung%2BGear%2BLive%2B-%2Bside%2Bview.JPG" height="320" width="315" /></a></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The display is bright, colourful and sharp - indoors, anyway. It’s a bit difficult to read in full sunlight (depending on what watch face design you use - some are more contrasty and therefore daylight-readable than others. (Recent updates in Android Wear 5 mean that you can temporarily brighten the back-light using “Sunlight mode”, and this helps a bit, but it’s still a bit hard to read in bright direct sunlight.)</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">And of course, there are dozens of downloadable watch face designs to choose from <a href="https://play.google.com/store/search?q=android+wear&c=apps&docType=1&sp=CAFiDgoMYW5kcm9pZCB3ZWFyegIYAIoBAggB">https://play.google.com/store/search?q=android+wear&c=apps&docType=1&sp=CAFiDgoMYW5kcm9pZCB3ZWFyegIYAIoBAggB</a> , or you can design your own with a suitable app. I use Intellicom Watch Faces for Android Wear </span><a href="https://play.google.com/store/apps/details?id=no.intellicom.lswatchface" style="text-decoration: none;"><span style="background-color: transparent; color: #1155cc; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;">https://play.google.com/store/apps/details?id=no.intellicom.lswatchface</span></a><span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"> , and I’ve designed this face, which is easy to read, and shows me the time and date, as well as the remaining battery charge on both my watch and phone:</span></div>
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<a href="http://4.bp.blogspot.com/-H_6z1tlM8Us/VLXF81KeESI/AAAAAAAAHRg/MVBFwSKC-OQ/s1600/screen%2Bbacklit.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://4.bp.blogspot.com/-H_6z1tlM8Us/VLXF81KeESI/AAAAAAAAHRg/MVBFwSKC-OQ/s1600/screen%2Bbacklit.png" /></a></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">I use the “Display always on” feature, which shows a “muted” watch display (to reduce battery drain) when you’re not actually looking at it - this is the “muted” version of my watch face:</span></div>
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<a href="http://2.bp.blogspot.com/-eVaHmFHS9AI/VLXF8VaXs4I/AAAAAAAAHRc/q7cfEg1WAls/s1600/screen%2Bbacklight%2Boff.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://2.bp.blogspot.com/-eVaHmFHS9AI/VLXF8VaXs4I/AAAAAAAAHRc/q7cfEg1WAls/s1600/screen%2Bbacklight%2Boff.png" /></a></div>
<b style="font-weight: normal;"><br /></b><span style="font-family: Arial; font-size: 15px; line-height: 1.15; white-space: pre-wrap;">I get through a full day even with the display always on. One thing that really bugged me with the old Sony was that you had to touch the watch to activate the display, which really limits its functionality as a watch, in my opinion. The muted display option in Android Wear does the job for me, while still giving me acceptable battery life.</span><br />
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Of course, Android Wear’s big party trick is voice-control - raise your watch to the normal viewing position, and say “OK Google” to activate it, and then tell / ask Google what you want it to do (e.g. "Remind me to ...", "Set a timer for ...", etc). It actually works very well - I get near-100% accuracy for my voice controls, even outdoors, or in moderately noisy environments. (If there's a lot of background noise, it can help to bring the watch closer to your mouth, but generally, it’s not necessary.) Of course, you do feel a bit of a dork talking to your watch, but I guess we’ll all get used to people talking to their wrists soon enough. If it bothers you, you can still access all functionality by tapping and swiping on the display, and the touch interface is very intuitive, especially if you’re already familiar with Android 5.</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Out of the box, your watch will present a lot of pre-loaded shortcuts, offering to “Send an sms to Jim” (who’s Jim?) or “Ask Eve if she is available on Friday night” (who’s Eve?) These are just prompts to help you get used to how you're "supposed" to use the watch, and they go away after a while, after you have started to interact with the Android Wear interface, when it thinks you’ve got the picture. Even when they’ve gone, if you tap and scroll down, you will see the "prompts", which can remind you of some of the sorts of things your watch can do, but you might have forgotten about. </span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Some of them are actions in themselves which require no further action (e.g. "Show me my steps" or “Show me my heart rate”), while others just start the next part of the instruction sequence, but still require additional voice input (e.g. "Send a text", after which it will prompt you first for an addressee, and then for the message content).</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">There is a growing collection of apps and games which you can load onto your Android Wear device. In many of these apps (especially the Google apps, which are heavily integrated), the main app resides on the phone, and there is an augmented "extension" which automatically uploads to the watch, and the user doesn't have to do anything to enable this – if you have a Wear-enabled app on your paired phone, the watch will automatically get the "extension" from the phone without you having to consciously do anything to enable it. </span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">E.g. cast a YouTube video from your phone to a Chromecast on your TV, and the YouTube player controls automatically pop-up on your watch, so you can pause, advance etc from your paired watch without needing to touch the phone. Or play music from your phone to your car's paired Bluetooth audio system or a Bluetooth speaker, and control it by talking to your watch (without needing to touch or even look at the screen), while your phone stays in your pocket: "OK Google ... play Rolling Stones"</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: bold; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">THAT'S </span><span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">what Android Wear is really all about!</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">There is also a growing collection of stand-alone apps and games for Android Wear, which have no UI on your phone. (You still install them via the paired phone, but that’s it - the only display / interaction is via the watch.) Some of them are OK, but ultimately, they’re all going to be limited by the small display size. (Which all seems a bit ironic to me - we’ve seen a trend for steadily increasing smartphone displays, from 3 ½ ” to 4” to 5” to 6” and even bigger - and now we’re going to start relying on a 1 ½” display?!) Most of the games and apps that you’re already used to are much more usable on your phone. Playing games and running productivity apps on the watch isn't really what I bought my Samsung Gear Live watch for - the real power of an Android Wear device to me is integration / extension of your smartphone's capabilities to a second-screen on your wrist. Nevertheless, it will be interesting to see what comes up in the next few months - I wonder what the first “killer app” for smartwatches will be?</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">I’ve heard lots of reports of “abysmal” battery life on pretty well all smartwatches (with the exception of the Pebble series, which use a B&W e-ink display). I get through a full day easily, with about 30% charge or more remaining, which is pretty much the same state my phone is in when I go to bed. I can live with that - sure, 3 days or more of battery life would be nice, but it’s never left me embarrassed by running flat part way through the day or evening. My nightly routine now means I plug both my phone and watch in for a charge, and I don’t see that as being a deal-breaker.</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Speaking of charging - the Samsung battery charger adapter isn’t very nice - it’s a cheap-feeling click-on plastic thing, and if you lose it or break it (or forget to pack it for a trip), you’ll be unable to recharge. </span></div>
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<a href="http://1.bp.blogspot.com/-NqTJf8R4-8I/VLXF7NQIk3I/AAAAAAAAHR0/-OPnrMvnBzM/s1600/Samsung%2BGear%2BLive%2BCharger.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://1.bp.blogspot.com/-NqTJf8R4-8I/VLXF7NQIk3I/AAAAAAAAHR0/-OPnrMvnBzM/s1600/Samsung%2BGear%2BLive%2BCharger.JPG" /></a></div>
<b style="font-weight: normal;"><br /></b><span style="font-family: Arial; font-size: 15px; line-height: 1.15; white-space: pre-wrap;">Wireless charging would be much nicer, but I guess that’s what you get for buying the cheapest Android Wear watch. I don’t think it’s particularly likely to break with sensible handling, and it lives by my bed, so there's not much risk of it going astray. (Given that I get comfortably through a full day, I don’t need to take the adapter to work for top-ups - but I might pick up a spare one anyway, just in case …)</span><br />
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">One nice feature that arrived with Android Wear 5: you now have the ability to download music from your phone to the watch, and pair your Bluetooth headphones directly to the watch, so that you can use it as a music player when you don’t have your phone handy. I always have my phone in my pocket, so while I’ve tested it and it works fine, this isn’t a feature that I’ll use much, but I can imagine it will appeal to people, who like running with a minimum of devices to weigh them down. (Of course, you’ll have no phone or messaging capacity if you run without your phone, but at least you can still listen to your music and tell the time, as well as get updates on your step-count and heart-rate.)</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><b>So … is it a must-have? </b></span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Well, for most people, probably not - yet. (Unless you’re tech-junky like me! At $188, the Samsung Wear Live is probably the cheapest way for experimenters and early adopters to experience Android Wear for themselves.)</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">It doesn't tell me anything that my phone doesn't tell me, but it does a lot without having to reach for my phone. I can discretely scan incoming calls, emails and text messages from my wrist, and decide whether I need t respond immediately. My phone’s battery life is significantly better than it was. Sure, some of this might be battery improvements in Lollipop 5.0.1 compared to KitKat 4.x, but some of it is certainly due to not actually reaching for my phone nearly as often as I used to.</span></div>
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<span style="font-family: Arial; font-size: 15px; vertical-align: baseline; white-space: pre-wrap;">I’m looking forward to seeing what new features and apps get added over the next few months.</span>Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-61564026020445418172014-10-24T12:58:00.002+10:002014-10-24T12:58:28.707+10:00Barska X-Trail 15x70 Binoculars - A Quick Review<div dir="ltr" style="line-height: 1.15; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Like all self-respecting amateur astronomers, I have a bad case of “Aperture Fever” - you never have enough aperture, and you can certainly never have too much!</span></div>
<b id="docs-internal-guid-5e6cbc60-4005-e6a6-46f6-576081cf292b" style="font-weight: normal;"><br /></b>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">I've been using my Pentax XCF 10x50 binoculars <a href="http://julianh72.blogspot.com.au/2014/08/quick-review-pentax-xcf-10x50-binoculars.html">http://julianh72.blogspot.com.au/2014/08/quick-review-pentax-xcf-10x50-binoculars.html</a> for stargazing for the past few months, and I'm still very happy with them - they deliver a lovely bright, sharp, wide-angle image. But I wanted more …</span></div>
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<div dir="ltr" style="line-height: 1.15; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">As is my habit, I started browsing eBay and other online shopping sites for something affordable in the 15x70 “giant” class, and I kept coming across the Barska X-Trail 15x70s </span></div>
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<span style="line-height: 18.399999618530273px;"><a href="http://www.barska.com/X-Trail_Binoculars-BARSKA_15x70_X-TRAIL_BINOCULARS_W_TRIPOD_ADAPTOR.html">http://www.barska.com/X-Trail_Binoculars-BARSKA_15x70_X-TRAIL_BINOCULARS_W_TRIPOD_ADAPTOR.html</a> . </span></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEihuOSQNnrjNx1NEBn9iTiL4zPPwcjznuDystQguSrupxL1ASZRmSq0GZF-BexgxydYe6-9F3-oRfPHi1wloHmm701EJW7GZdwld4tukZIXluwbMGea3Dg3Ct-cP0kSdnvSzRNiRRooipI/s1600/Barska+15x70.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEihuOSQNnrjNx1NEBn9iTiL4zPPwcjznuDystQguSrupxL1ASZRmSq0GZF-BexgxydYe6-9F3-oRfPHi1wloHmm701EJW7GZdwld4tukZIXluwbMGea3Dg3Ct-cP0kSdnvSzRNiRRooipI/s1600/Barska+15x70.JPG" height="320" width="317" /></a></div>
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<span style="font-family: Arial; font-size: 15px; line-height: 1.15; white-space: pre-wrap;">The key specs are as follows:</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Magnification: 15x</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Objective Lens: 70 mm</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Prism type: Porro, BAK-4</span></div>
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<li dir="ltr" style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; list-style-type: disc; text-decoration: none; vertical-align: baseline;"><div dir="ltr" style="line-height: 1.15; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Exit Pupil: 4.7 mm (70 mm / 15x)</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Optical Coating: Fully Coated</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Field of View: 77 m @ 1000 m (4.4 degrees Actual FoV; 65 degrees Apparent FoV)</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Close Focus: 15 m</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Eye Relief: 20 mm</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Weight: 1270 g</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Included Accessories: Mini Table-Top Tripod, Tripod Adaptor, Soft Carrying Case, Neck Strap, Lens Covers and Lens Cloth</span></div>
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<b style="font-weight: normal;"><br /></b>
<div dir="ltr" style="line-height: 1.15; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">They ticked pretty well all of the boxes for me. About the only thing I could criticize is that they are only “Fully Coated” rather than “Fully Multi-Coated” - but for the low asking price, I figured I could live with this “omission”.</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Plus of course, there's the open question of build and optical quality … They seemed to get good reviews overall, and they are certainly affordable, so there was only one way to find out….</span></div>
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<div dir="ltr" style="line-height: 1.15; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">I found an international seller who offered them for AU$94.95, including expedited delivery to Australia, so I took the plunge and ordered a pair on Thursday last week - and they were delivered in Brisbane exactly one week later - very happy with that!</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The binoculars came very well packed, and arrived without any damage. I unpacked them and took a look at what I had bought.</span></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiaGd1GjMOsRHDkPdtqqOU2L8aZec7tFuo_5jaHVXGOTWlAJ_bj0s2Rji142bwETdeJXniAJ1JD8k3VtdgnW9YtIgqXXPUZdmn0er9TmEXn_Z59Uft5tfI44dGoqkLbS8qQfPynqTgK31Q/s1600/IMG_20141023_230543.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiaGd1GjMOsRHDkPdtqqOU2L8aZec7tFuo_5jaHVXGOTWlAJ_bj0s2Rji142bwETdeJXniAJ1JD8k3VtdgnW9YtIgqXXPUZdmn0er9TmEXn_Z59Uft5tfI44dGoqkLbS8qQfPynqTgK31Q/s1600/IMG_20141023_230543.jpg" height="239" width="320" /></a></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjiIAL6XkBKdgzFwtjpergkBfgy65_1ouhB732LKdXQnAruS7yploiQls1Yvpwg6H-krqgR2OtkBV6Fk4op7prV9ojSH23SDjSohnpcgpBL9DGNClA7Vdy-V0RgXh_pTxzeQejcCg-agxg/s1600/IMG_20141023_230527.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjiIAL6XkBKdgzFwtjpergkBfgy65_1ouhB732LKdXQnAruS7yploiQls1Yvpwg6H-krqgR2OtkBV6Fk4op7prV9ojSH23SDjSohnpcgpBL9DGNClA7Vdy-V0RgXh_pTxzeQejcCg-agxg/s1600/IMG_20141023_230527.jpg" height="239" width="320" /></a></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The binoculars themselves feel solidly built and have a nice “heft” and balance. The fold-down cup on the right eyepiece is a bit "buckled" (I guess it has been "crushed" in the box for some time) - I'm not sure if it will straighten out over time, but it doesn't detract form the use of the binoculars. Apart from that, no problems at all.</span></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg_EgikfuLnzmrGuPQ-VYQfzlvEKC202le5e0HMAby4mX0YYsEX0McnP_GtNmq6nXAg57eUslTy883PKkqfRerFqdYtyI-VlO0iw2aMNOCA7Me4trY9VYzp9oVpwQhxwY1vEBiVEkp_uSs/s1600/IMG_20141023_230629.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg_EgikfuLnzmrGuPQ-VYQfzlvEKC202le5e0HMAby4mX0YYsEX0McnP_GtNmq6nXAg57eUslTy883PKkqfRerFqdYtyI-VlO0iw2aMNOCA7Me4trY9VYzp9oVpwQhxwY1vEBiVEkp_uSs/s1600/IMG_20141023_230629.jpg" height="239" width="320" /></a></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiqKy7ZpHQpfBUx5VJovkq1vWxt9JmMSg-QbYiffbGlHsaJJoIT6KWH7Q-1hFfrYxek6ZXKLihx-hfB2sOjFKdTm87eqoHN276bpqOSo0hg8wCombUKBzrU_a1__vRWvPO5zUnO0d0qfdI/s1600/IMG_20141023_230637.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiqKy7ZpHQpfBUx5VJovkq1vWxt9JmMSg-QbYiffbGlHsaJJoIT6KWH7Q-1hFfrYxek6ZXKLihx-hfB2sOjFKdTm87eqoHN276bpqOSo0hg8wCombUKBzrU_a1__vRWvPO5zUnO0d0qfdI/s1600/IMG_20141023_230637.jpg" height="239" width="320" /></a></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><br /></span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The table-top tripod and tripod adapter are somewhat surprisingly not complete rubbish - the tripod is metal and seems quite sturdy, but I'm not sure how often I will have a table to set them up on, and in any case, you can really only use them near-horizontal on such a small tripod, so it is really only useful for terrestrial viewing.</span></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEje7BqNgvw8sH2AKqIYhUIOh-RPkrUVq-bcnnb1MO8bRuHSbmlkJqn_xjocM2d78ynROSayr-kGHv6H9Vxx35nEJtzYdxwiQXsqYMaV06sjD0xiqwbjOgSg1BM3A1c8SrS5ALIT-OF4_t0/s1600/IMG_20141023_230509.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEje7BqNgvw8sH2AKqIYhUIOh-RPkrUVq-bcnnb1MO8bRuHSbmlkJqn_xjocM2d78ynROSayr-kGHv6H9Vxx35nEJtzYdxwiQXsqYMaV06sjD0xiqwbjOgSg1BM3A1c8SrS5ALIT-OF4_t0/s1600/IMG_20141023_230509.jpg" height="239" width="320" /></a></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhNHldBtz3WXymYSYZr6Eok1QCBuFlRmXi3cQqpvbC-Ng5Pu2VqUltn1h5AokOQ8kj6GP8LrgdPAuyddqjJ0y_gC8A_Hy3fhdPUkDauiXo0N1Cfem4vrO2JqjmR28vDveIUWWa_DSCLP28/s1600/IMG_20141023_230603.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhNHldBtz3WXymYSYZr6Eok1QCBuFlRmXi3cQqpvbC-Ng5Pu2VqUltn1h5AokOQ8kj6GP8LrgdPAuyddqjJ0y_gC8A_Hy3fhdPUkDauiXo0N1Cfem4vrO2JqjmR28vDveIUWWa_DSCLP28/s1600/IMG_20141023_230603.jpg" height="239" width="320" /></a></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The carry case and neck strap are pretty basic (the neck strap is really WAY too thin for hanging these babies around your neck!), so an upgrade to a better wider padded strap is on the cards. The case is thin and soft, with minimal padding, so won't provide much protection from bumps and knocks, but my binoculars will live safely at home, and the case is really only going to be a dust cover, so I can live with that.</span></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhm01A5nmigdBKydqvjHsXSheYKyrWH50_b1Sy5FG6t-AAmpEY_7Qa_uovVpR06OjlGyWH1kateegpixweTo0clAB73U86v7LyW4CGXL2MW2crcQnaUwpE8iSlu8-Qz0iCI-XsfNWh9qFQ/s1600/IMG_20141023_230621.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhm01A5nmigdBKydqvjHsXSheYKyrWH50_b1Sy5FG6t-AAmpEY_7Qa_uovVpR06OjlGyWH1kateegpixweTo0clAB73U86v7LyW4CGXL2MW2crcQnaUwpE8iSlu8-Qz0iCI-XsfNWh9qFQ/s1600/IMG_20141023_230621.jpg" height="239" width="320" /></a></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><br /></span></div>
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<div dir="ltr" style="line-height: 1.15; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">I was pleased to find they were perfectly collimated, and provide a bright, sharp image all the way to the edge of the 65-degree apparent field of view (4.4-degrees actual field of view at 15x magnification). </span></div>
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<div dir="ltr" style="line-height: 1.15; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">There’s a bit of distortion and Chromatic Aberration at the edge of the field of view, if you look hard, but because these have a nice wide field of view, it really doesn't detract from the overall view. The distortion is there, but you can only really see it if you position a straight line (such as a building or power pole) near the edge of the field of view; it’s basically not noticeable on more “natural” targets. The CA is only apparent on bright, high-contrast targets near the edge of the field of view. These defects are only apparent if you switch your gaze from the centre to the periphery, and the effect disappears if you swing the binoculars to bring the main target more central.</span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">But of course it was really their night-time use that I really wanted to test out!</span></div>
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<div dir="ltr" style="line-height: 1.15; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">When the Sun had set, and family duties had been attended to, I settled down in a camping chair in the back yard with my Pentax 10x50s, my new Barska 15x70s, and a couple of tripods. It’s New Moon at the moment, so checking out the Moon is out of the question for a few days, so my first targets were some old favourites that were favourably positioned - the globular cluster 47 Tucanae (NGC 104), the Great Nebula in Orion (M42), Andromeda Galaxy (M31), and Ptolemy’s Cluster (M7). I swapped back and forth between the two binoculars a few times on each target, to compare the views. </span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;"><br /></span></div>
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<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">And I was very impressed!</span></div>
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<div dir="ltr" style="line-height: 1.15; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">Stars were shown as pin-sharp points of light across the field - the CA and distortion that could be picked up by selecting suitable “test targets” in daylight really isn't apparent at all for stargazing use. (I suspect it will be more apparent on a bright target like the Moon, but again, should only be noticeable at the periphery rather than in the central view.)</span></div>
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<div dir="ltr" style="line-height: 1.15; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The 15x70s show significantly more stars than the 10x50s, and the higher magnification tends to darken the background sky as well, which also helps in seeing very faint stars, and brings diffuse targets such as nebulae and galaxies into better contrast against the sky. Looking at nebulae and galaxies revealed a bigger apparent area (as the fainter edges could be resolved more clearly), and showed more detail and "structure" within the “body” of the nebulae as well - and all at 50% higher magnification than the 10x50s. The 4.4 degree field of view is ample for viewing pretty well any night-sky target, apart perhaps from seeing an entire constellation in a single view, for which the 10x50s with their 6.5 degree field might be preferable.</span></div>
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<div dir="ltr" style="line-height: 1.15; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">The 10x50s are light and compact enough to be held steady for extended periods, but the bigger and heavier 15x70s definitely test your endurance after a short period. My tripods just aren’t the right size and shape for convenient binocular stargazing use while sitting in a comfortable chair (you really need a parallelogram arm for this), and of course the higher magnification amplifies the shakes. However, I found that folding up the legs of a tripod to make a monopod worked very well (especially with the pan / tilt head) - just plant the base of the “monopod” on the ground ahead of you, and lean it back to bring the binoculars up to your face, and use the pan / tilt to get the alignment just right; then lock the pan / tilt, and you have a nice steady platform which requires virtually no arm support other than a bit of light guiding.</span></div>
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<div dir="ltr" style="line-height: 1.15; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">While playing around, I also found that the supplied table-top tripod also makes a handy “pistol grip” mount, which allows you to hand-hold the binoculars much more steady than conventional hand-held use. I folded the three legs together to make a single “grip” for my left hand, and turned the pan / tilt handle 90 degrees to the right (rather than it's normal orientation in-line with the binoculars); then holding the pan / tilt handle in my right, it is actually possible to hold the binoculars much more steadily and comfortably than the normal handheld position. I'm not sure why this is - it’s probably because your arms are comfortably resting down on your chest rather than being held elbows-out in front of your chest, but if you doubt me, try it - it might work for you too!</span></div>
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<div dir="ltr" style="line-height: 1.15; margin-bottom: 0pt; margin-top: 0pt;">
<span style="background-color: transparent; color: black; font-family: Arial; font-size: 15px; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;">All in all, I’m very happy with my purchase! My only quibble is that I now have even more equipment to cart around - the 10x50s give a wonderful wide view for hand-held terrestrial and “wide sky” use (e.g. meteor spotting), and are light enough to throw in a backpack, but the 15x70s will be my “go to” binoculars for stargazing use, especially when I have a chair and a “monopod” to make them comfortable to use for extended viewing sessions.</span></div>
Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-41909047955454359222014-10-21T15:46:00.005+10:002014-10-21T15:46:59.979+10:00Have you ever wanted to know what that bright light was that you just saw whizzing past overhead?While it COULD have been a UFO or a meteorite, if it was evening (or pre-dawn), and it didn't look like an aeroplane, then there's a good chance that it was a satellite of some sort.<br />
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"Heavens Above" <a href="http://www.heavens-above.com/main.aspx">http://www.heavens-above.com/main.aspx</a> is a great resource for finding out what that thing was, or for getting notifications in advance of upcoming visible spacecraft fly-overs.<br />
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In particular, keep a look-out for the International Space Station and the "Iridium Flashes" in your neighbourhood - these can be VERY bright!<br />
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There is now also a "prototype" version of "Heavens Above" which is designed specifically for Mobile Devices - access it from your phone or tablet here: <a href="http://www.heavens-above.com/mobile">http://www.heavens-above.com/mobile</a><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhDwDPB8Q-yPiC1HAyKKLrMg8332ElbCJ9_yv3AkZ-LT1f4xnEzZq-wWxys3TstABI1sXrVh8wPngvJ22Q1Omh_d3wc_HT2g-vLXNSgfgXaEuOgBT6yhbyH_ukZ-iqa-BbAvb-0fDqvkbg/s1600/Heavens+Above+Mobile.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhDwDPB8Q-yPiC1HAyKKLrMg8332ElbCJ9_yv3AkZ-LT1f4xnEzZq-wWxys3TstABI1sXrVh8wPngvJ22Q1Omh_d3wc_HT2g-vLXNSgfgXaEuOgBT6yhbyH_ukZ-iqa-BbAvb-0fDqvkbg/s1600/Heavens+Above+Mobile.png" height="320" width="186" /></a></div>
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Now there's no longer any need to print out your satellite-pass charts and tables before heading outside for a spot of spacecraft-spotting - just take your phone / tablet with you, and get real-time tables and charts on demand.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjxz3irIEkvaMVdlBM_hjhk6H8U9uuq8iSx5og4doPsOxXV5VmyzLFYmkk7QTz-YL-P_YjDDQCv49Nt-DnY0boDZl6zso5JfC3lLg8GBmcG86qRx45HJ8xhcSL7UyqP1Cs5Ldui1TU-RDU/s1600/Heavens+Above+Mobile+table.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjxz3irIEkvaMVdlBM_hjhk6H8U9uuq8iSx5og4doPsOxXV5VmyzLFYmkk7QTz-YL-P_YjDDQCv49Nt-DnY0boDZl6zso5JfC3lLg8GBmcG86qRx45HJ8xhcSL7UyqP1Cs5Ldui1TU-RDU/s1600/Heavens+Above+Mobile+table.png" height="320" width="199" /></a></div>
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The main features are as follows:<br />
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<ul>
<li><i>"Live sky" chart will show you all the current visible satellites as they move across the sky. This is probably the most convenient display for an evening's viewing, as no navigation between pages is necessary.</i></li>
<li><i>Predictions include all visible satellites up to a configured magnitude cutoff, plus Iridium flares.</i></li>
<li><i>Javascript automatically refreshes the predictions when necessary and stores them locally on your device. Once you have downloaded the data for the next 24 hours, an Internet connection is no longer necessary.</i></li>
<li><i>Sky charts are generated on the client using Javascript.</i></li>
<li><i>Location can be obtained from the phone itself using the HTML5 geolocation service.</i></li>
<li><i>The site is implemented as a single HTML file and so transitions between pages do not require fetching data from the server.</i></li>
<li><i>Runs on any device with an HTML5 capable browser (most modern Android and iOS devices).</i></li>
<li><i>Makes use of the jQuery Mobile framework for a consistent "look and feel".</i></li>
<li><i>Pages are currently optimised for the smart phone format, but can also be used on tablets. A tablet-optimised layout will be available shortly.</i></li>
<li><i>The first version of the prototype is only available in the English language, but other languages will follow.</i></li>
</ul>
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Very neat!Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-32622316799892012182014-10-15T15:18:00.001+10:002014-10-15T15:18:11.801+10:00M6 "Butterfly Cluster" shot with ZWO ASI120MC on Celestron 130 mm Netwonian<div class="MsoNormal">
This is the M6 "Butterfly Cluster" <a href="http://en.wikipedia.org/wiki/Butterfly_Cluster">http://en.wikipedia.org/wiki/Butterfly_Cluster</a> :</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjcc41pObB9xUKh0LSIV85CShG9iSh29evkbWWOJBDoNCCoK7Pmkuoun_EQ1zRjljhwdcMBvnaS7SUm82QiXhFQJ6mhW4fJ-UNvTHidp0_lZHaDa5ZYIH2thLsh5phrbQoELYmGsPrFla8/s1600/M6+Butterfly+Cluster+-+14-Oct-2014.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjcc41pObB9xUKh0LSIV85CShG9iSh29evkbWWOJBDoNCCoK7Pmkuoun_EQ1zRjljhwdcMBvnaS7SUm82QiXhFQJ6mhW4fJ-UNvTHidp0_lZHaDa5ZYIH2thLsh5phrbQoELYmGsPrFla8/s1600/M6+Butterfly+Cluster+-+14-Oct-2014.jpg" height="240" width="320" /></a></div>
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This is a 5-second exposure taken last night (14 October) with my ZWO ASI120MC astro-camera mounted
on my 130 mm Newtonian telescope. The field of view is about 30
arc-minutes x 20 arc-minutes. (That is, the full Moon would just about fit in
the long dimension of the image, but would more than cover the short
dimension.)</div>
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<o:p></o:p></div>
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The brightest star is V862 Scorpii at magnitude 6.76 (the slightly yellowish white star just below the centre of the image). The faintest visible stars are about Magnitude 11.5 - not bad for a 5 second exposure! The colours are all pretty accurate, when I compare with standard planetarium software.</div>
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Here is a B&W negative image, which can make it easier to pick out the fine detail:</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgvmPmfIiJPaH6ypTED_MBOLCULx0dVhi_qej8r4GreRel97AXK9c0TZw-8G34wDNFmhNg58SVhZseeMgpcPZCuBIxb_xhdj2hXFYwfjZWJn9JoH4RfXvk0bWioxLmRsQk0pXGCTixAcfQ/s1600/M6+Butterfly+Cluster+-+Monochrome+Negative+-+14-Oct-2014.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgvmPmfIiJPaH6ypTED_MBOLCULx0dVhi_qej8r4GreRel97AXK9c0TZw-8G34wDNFmhNg58SVhZseeMgpcPZCuBIxb_xhdj2hXFYwfjZWJn9JoH4RfXvk0bWioxLmRsQk0pXGCTixAcfQ/s1600/M6+Butterfly+Cluster+-+Monochrome+Negative+-+14-Oct-2014.jpg" height="240" width="320" /></a></div>
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One nice thing about shooting stars digitally (rather than on
film as in the “bad old days”): </div>
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For any given set of exposure settings, on a
digital image there is a really nice linear relationship between the diameter
of the star image and the apparent magnitude of the star. (When shooting time
exposures on film, the relationship between the image diameter and the actual
brightness of the star is much more complex.) This graph shows the
relationship for a selected sample of stars on this particular image (bearing
in mind I was only measuring the apparent diameters to about 0.5 mm accuracy
when printed at A3 size). </div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjlWUJOxMnxeGt2rxjmptDvzDZza_Up4jd0fKyW92VEFQXMlgcPglceDfN7wFgZmJO7_CvJvKHRKuoR6G8Mgv_0yVsPGlEdoF_0s0QJN5eS6H2QshfV5xkGu-7aMjFeIimZTWFBbV3TJlw/s1600/Magnitude+vs+Diameter.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjlWUJOxMnxeGt2rxjmptDvzDZza_Up4jd0fKyW92VEFQXMlgcPglceDfN7wFgZmJO7_CvJvKHRKuoR6G8Mgv_0yVsPGlEdoF_0s0QJN5eS6H2QshfV5xkGu-7aMjFeIimZTWFBbV3TJlw/s1600/Magnitude+vs+Diameter.JPG" height="210" width="320" /></a></div>
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This means that with a few stars of known magnitude
in frame, you can estimate the magnitude of all the other stars. I'll have to
try this on a few variable stars and see if I can measure their variability, and
do some “real science”!<o:p></o:p></div>
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Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-84609271584634539572014-10-15T09:35:00.001+10:002014-10-15T09:35:08.061+10:00Free Astronomy courses on Coursera - highly recommended!Rutgers University is offering the 6-week "Analyzing the Universe" course free on Coursera, and it has just kicked off today:<br />
<a href="https://class.coursera.org/analyze-002">https://class.coursera.org/analyze-002</a><br />
This one looks like it is fairly analytical, but shouldn't be impossible if you remember a bit of your high school physics and maths.<br />
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For people who are looking for something at a bit more "introductory" level, the highly-regarded Duke University "Introduction to Astronomy" course is starting again on December 1 2014, and is open for enrolments on Coursera now:<br />
<a href="https://www.coursera.org/course/introastro">https://www.coursera.org/course/introastro</a><br />
<br />
Earlier this year, I did the "AstroTech" course offered by Edinburgh University <a href="https://class.coursera.org/astrotech-001">https://class.coursera.org/astrotech-001</a>, which was a really good introduction to the technology used by modern astronomers - this one had a pretty light "theory" load, so would suit amateur astronomers with any level of formal science / maths education.<br />
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For something which was a lot more challenging, but absolutely fascinating, take a look at "The Science of the Solar System" <a href="https://class.coursera.org/solarsystem-001">https://class.coursera.org/solarsystem-001</a>, presented by "Pluto Killer" Mike Brown <a href="http://en.wikipedia.org/wiki/Michael_E._Brown">http://en.wikipedia.org/wiki/Michael_E._Brown</a> of CalTech.<br />
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If you're not familiar with Coursera <a href="https://www.coursera.org/">https://www.coursera.org/</a>, don't be afraid to take a look and enrol. There is a huge variety of courses being offered by universities all over the world, and it's all free. (Some courses give you the option of signing up to earn a formal certificate for a modest fee, but I haven't bothered with this, as I am doing these courses purely for my own self-education, not for any formal recognition.)Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0tag:blogger.com,1999:blog-108699730814653894.post-59176614610722687612014-10-08T13:43:00.000+10:002014-10-08T13:43:02.234+10:00First shots of the Moon with ZWO ASI120MCEnough tinkering with the hardware and cooling, etc - it's time to take some pictures!<br />
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North Polar region, taken on 2 October 2014 with 130 mm Newtonian (FL = 650 mm):<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjeKl838Jrc81dT2fErdaR3RzdFPFJj3dmHpjkG07TJoj3d0t0hWJTmJXIkokNNbe2kY55nA2I_TYX00Qxex4CUec_M2TcCnAJSEKgK0VoqpY3mq6P8CjBkIXFqB4v9xyTqPppivkcaWnA/s1600/Moon_212559_g3_ap248_conv.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjeKl838Jrc81dT2fErdaR3RzdFPFJj3dmHpjkG07TJoj3d0t0hWJTmJXIkokNNbe2kY55nA2I_TYX00Qxex4CUec_M2TcCnAJSEKgK0VoqpY3mq6P8CjBkIXFqB4v9xyTqPppivkcaWnA/s1600/Moon_212559_g3_ap248_conv.jpg" height="239" width="320" /></a></div>
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South Polar region, taken on 2 October 2014 with 130 mm Newtonian (FL = 650 mm):<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjesthK_RTCzk0OHz3j4AcEGuCgx0gjRfw9ofQO1FWb9QnSN5sOKUkzGkYD_mL4iutRAbDA6QdhyMhtFxIvR37Wjk39h0_2VnyYatnKUM0ctYDvIvaFuVuoBJgSQIfYJNPQ-8wRR9vOTGY/s1600/Moon_212720_g3_ap259_conv.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjesthK_RTCzk0OHz3j4AcEGuCgx0gjRfw9ofQO1FWb9QnSN5sOKUkzGkYD_mL4iutRAbDA6QdhyMhtFxIvR37Wjk39h0_2VnyYatnKUM0ctYDvIvaFuVuoBJgSQIfYJNPQ-8wRR9vOTGY/s1600/Moon_212720_g3_ap259_conv.jpg" height="239" width="320" /></a></div>
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And a rough composite of the above two images:<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgf4Zo69c9s4Cwoynkqr1pit_1q2VQFe-TBAq0geGPm9G3yxJk6H6u6kTxdA8haU1SdVMErhszUcgov9QindmF9PVWTyOjd147J2xAYQ8mMEsJUCTUOlj14u2VaeeKCHvNiI73MId-fZ2A/s1600/Moon+-+Composite+-+2+October+2014+-+cropped.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgf4Zo69c9s4Cwoynkqr1pit_1q2VQFe-TBAq0geGPm9G3yxJk6H6u6kTxdA8haU1SdVMErhszUcgov9QindmF9PVWTyOjd147J2xAYQ8mMEsJUCTUOlj14u2VaeeKCHvNiI73MId-fZ2A/s1600/Moon+-+Composite+-+2+October+2014+-+cropped.jpg" height="296" width="320" /></a></div>
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Tycho crater and rays (in the South polar region), taken on 6 October 2014 with 90 mm Maksutov (FL = 1200 mm):<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiqbhC1T-DMT6Dt4eAubr6Ird_6rIlgcu6uwgLnwSSSbGDDI3MI822bITXoVcjTVQ5DP9aGlx19Z2bcGpEf3dmkBxVAIpGD8FQyIHjIgdyhY4L09hggX1q6tMdN24gXvAXB_aXon293bpg/s1600/Tycho+-+06-Oct-2014.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiqbhC1T-DMT6Dt4eAubr6Ird_6rIlgcu6uwgLnwSSSbGDDI3MI822bITXoVcjTVQ5DP9aGlx19Z2bcGpEf3dmkBxVAIpGD8FQyIHjIgdyhY4L09hggX1q6tMdN24gXvAXB_aXon293bpg/s1600/Tycho+-+06-Oct-2014.png" height="237" width="320" /></a></div>
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<br />Julian Hardyhttp://www.blogger.com/profile/12454804345885642079noreply@blogger.com0